Marine Weather and Tide Forecast for Brunswick, ME
 | Sunrise 5:38 AM Sunset 7:51 PM Moonrise 9:03 PM Moonset 8:10 AM |
Marine Forecasts
NOTE: Zones were updated 3/20/2025. If your report is out of date, please click Edit
ANZ153 Casco Bay- 500 Am Edt Mon Aug 11 2025
Today - SW winds around 5 kt, becoming S this afternoon. Seas 2 to 3 ft. E swell up to 3 ft at 4 seconds. Light swells. Patchy fog early this morning with vsby 1 to 3 nm.
Tonight - SW winds around 5 kt. Seas 2 to 3 ft. E swell up to 3 ft at 4 seconds. Light swells. Patchy fog after midnight with vsby 1 to 3 nm.
Tue - SW winds around 5 kt, becoming S in the afternoon. Seas 2 to 3 ft. E swell up to 3 ft at 4 seconds. Light swells. Patchy fog in the morning with vsby 1 to 3 nm.
Tue night - S winds 5 to 10 kt. Seas 2 to 3 ft. E swell up to 3 ft at 6 seconds. Light swells. Patchy fog after midnight with vsby 1 to 3 nm.
Wed - SW winds 5 to 10 kt, becoming S 10 to 15 kt with gusts up to 20 kt in the afternoon. Seas 2 to 3 ft. E swell up to 3 ft at 7 seconds. Light swells. Patchy fog in the morning with vsby 1 to 3 nm.
Wed night - SW winds 5 to 10 kt. Seas 2 to 3 ft. E swell up to 3 ft at 5 seconds. Light swells. A chance of showers.
Thu - SW winds 5 to 10 kt. Seas 2 to 3 ft. S swell up to 3 ft at 5 seconds. Light swells. A chance of showers in the afternoon.
Thu night - NW winds 5 to 10 kt, becoming N after midnight. Seas around 2 ft. SE swell up to 2 ft at 5 seconds. Light swells.
Fri - N winds 5 to 10 kt, becoming se in the afternoon. Seas around 2 ft. SE swell up to 2 ft at 4 seconds. Light swells.
Fri night - SW winds around 5 kt, becoming W around 5 kt after midnight. Seas around 2 ft. SE swell up to 2 ft at 4 seconds. Light swells.
ANZ100 500 Am Edt Mon Aug 11 2025
Synopsis for stonington me to merrimack river ma out to 25 nm the weather remains in the grips of high pressure through early this week with prevailing south to southwest flow a cold front approaches toward midweek and crosses the waters late Thursday or Thursday night. High pressure builds in behind the front by late week. Overall winds are expected to remain light with seas below 5 feet.
7 Day Forecast for Marine Location Near Brunswick, ME
NEW! Add second zone forecast
| Brunswick Click for Map Mon -- 03:20 AM EDT 4.40 feet High Tide Mon -- 05:39 AM EDT Sunrise Mon -- 08:09 AM EDT Moonset Mon -- 11:39 AM EDT -0.23 feet Low Tide Mon -- 03:51 PM EDT 4.11 feet High Tide Mon -- 07:49 PM EDT Sunset Mon -- 09:03 PM EDT Moonrise Mon -- 11:53 PM EDT -0.01 feet Low Tide Tide / Current data from XTide NOT FOR NAVIGATION |
Brunswick, Maine, Tide feet
| 12 am |
| 0.5 |
| 1 am |
| 1.9 |
| 2 am |
| 3.4 |
| 3 am |
| 4.3 |
| 4 am |
| 4.3 |
| 5 am |
| 4 |
| 6 am |
| 3.4 |
| 7 am |
| 2.6 |
| 8 am |
| 1.7 |
| 9 am |
| 0.9 |
| 10 am |
| 0.2 |
| 11 am |
| -0.2 |
| 12 pm |
| -0.2 |
| 1 pm |
| 0.8 |
| 2 pm |
| 2.4 |
| 3 pm |
| 3.7 |
| 4 pm |
| 4.1 |
| 5 pm |
| 3.9 |
| 6 pm |
| 3.5 |
| 7 pm |
| 2.8 |
| 8 pm |
| 2 |
| 9 pm |
| 1.2 |
| 10 pm |
| 0.5 |
| 11 pm |
| 0.1 |
| Upper Hell Gate (Sasanoa River Click for Map Mon -- 01:33 AM EDT 1.07 knots Max Flood Mon -- 05:25 AM EDT -0.00 knots Slack Mon -- 05:39 AM EDT Sunrise Mon -- 07:47 AM EDT -1.09 knots Max Ebb Mon -- 08:09 AM EDT Moonset Mon -- 11:13 AM EDT 0.00 knots Slack Mon -- 02:03 PM EDT 1.08 knots Max Flood Mon -- 05:59 PM EDT -0.00 knots Slack Mon -- 07:48 PM EDT Sunset Mon -- 08:10 PM EDT -0.95 knots Max Ebb Mon -- 09:02 PM EDT Moonrise Mon -- 11:19 PM EDT 0.00 knots Slack Tide / Current data from XTide NOT FOR NAVIGATION |
Upper Hell Gate (Sasanoa River, Maine) Current, knots
| 12 am |
| 0.7 |
| 1 am |
| 1 |
| 2 am |
| 1 |
| 3 am |
| 0.9 |
| 4 am |
| 0.6 |
| 5 am |
| 0.2 |
| 6 am |
| -0.4 |
| 7 am |
| -0.9 |
| 8 am |
| -1.1 |
| 9 am |
| -0.8 |
| 10 am |
| -0.5 |
| 11 am |
| -0.1 |
| 12 pm |
| 0.4 |
| 1 pm |
| 0.9 |
| 2 pm |
| 1.1 |
| 3 pm |
| 1 |
| 4 pm |
| 0.8 |
| 5 pm |
| 0.5 |
| 6 pm |
| -0 |
| 7 pm |
| -0.6 |
| 8 pm |
| -0.9 |
| 9 pm |
| -0.8 |
| 10 pm |
| -0.5 |
| 11 pm |
| -0.1 |
Area Discussion for Gray/Portland, ME
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FXUS61 KGYX 110757 AFDGYX
Area Forecast Discussion National Weather Service Gray ME 357 AM EDT Mon Aug 11 2025
SYNOPSIS
High pressure remains in control for the next few days, and temperatures continue to rise through the first half of this week as a ridge of high pressure builds over the Northeast. The ridge starts to break down mid week and that will allow for some chances of showers and thunderstorms as a cold front approaches. The weekend looks to be dry at this time with a warming trend possible by Sunday.
NEAR TERM /UNTIL 6 PM THIS EVENING/
355AM Update...Just resending to add a climate section as forecast temperatures could threaten daily record highs today through Wednesday.
Previous...
There will be patchy fog in some areas this morning, especiallthreateny within river valleys, but once this clears by 8 to 9 AM, the focus remains on the heat with temperatures expected to climb even higher than yesterday. A strong ridge of high pressure builds directly overhead today bringing mostly sunny, hot and dry conditions. 850mb temps of +18C to +20c supports highs reaching the lower to mid 90s across much of the interior today with heat indices likely above 95F for a few hours this afternoon across the Maine interior/foothills stretching into southeastern NH, where the Heat Advisory is in place. Looking back at the past few days, NBM and MAV guidance have had consistent a cool bias away from the coast, possibly due to how dry it is. So I've played the persistence card on temps today by going a degree or so above the NBM, but this doesn't really change the overall message of it's going to be hot regardless. A little more moisture toward the mountains may result in a shower or two this afternoon but mainly just a tad more in the way of clouds than southern areas.
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/
Fortunately there will be some relief to the heat tonight.
Mostly clear skies and light winds will allow for radiational cooling, and since the airmass is not as humid as past heat events this summer, temperatures will be able to reach the low to middle 60s for lows, possibly even the upper 50s in some of the northern valleys. Speaking of valleys, valley fog will probably develop in many areas and possibly the Augusta and Midcoast regions as well.
The synoptic patterns remains largely unchanged with strong ridge of high pressure remaining directly overhead for Tuesday, bringing nearly identical conditions to those of today: hot and mostly sunny with only a very low chance of a shower or two in the mountains. Temperatures away from the coast are expected to reach the low to mid 90s, possibly even upper 90s in some spots, with heat index values likely exceeding 95F for a few hours in many areas, where the Heat Advisory remains. Those not in the Heat Advisory can still expected heat indices in the 90-95F range, even closer to the coast before the seabreeze moves ashore in the afternoon.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/
Early morning long-term update...
Key messages from the previous shift remain the same through Wednesday as another hot day is expected. There's a good chance that the heat advisory will have to be extended for Wednesday.
The same holds with precipitation chances as the best chance for at least widely scattered showers and thunderstorms looks to be during the afternoons Wed and Thu. Widespread rains are not expected however.
Previously...
Key Messages: * Heat continues Wednesday with highs in the upper 80s to mid 90s. A Heat Advisory with continuation into Wednesday likely.
* Cold front approaches Wednesday, decreasing temperatures late week.
Details: Continued to increase temperatures Wednesday from the NBM deterministic. Combination of dry surface conditions and mostly sunny skies should allow for quick morning warmup to around 90 for much of the forecast area. From here, highs push into the low to mid 90s across the interior and even mtn valleys. Along the coast (especially the Midcoast), light onshore flow will tend to strengthen in the afternoon, reinforced by seabreeze. Thus, temps along the coast peak early afternoon, with a moderating airmass for remainder of the day.
The good news, despite this longer period of heat, is the relative dryness of the airmass as well as good overnight recovery temperatures in the 60s. Dewpoint temps will tend to run low considering dry antecedent surface conditions, but there won't be enough momentum transfer to mix down even drier values.
This keeps heat index values close to actual temperatures.
Given the confidence in this airmass, an extension to the Heat Advisory will likely be needed for Wednesday, but next incoming cold front offers some uncertainty in cloud cover and possible showers.
Consensus does keep precipitation largely west of the CWA into early Wed afternoon, but can expect some clouds ahead. With building CAPE and forcing, could see some showers and thunderstorms develop ahead of the main forcing. However, lapse rates are not steep and shear of around 20 kts could prevent a more widespread thunder event.
Winds shift NW behind the front Thursday, with a dip in expected high temperatures late week into the mid to lower 80s.
AVIATION /08Z MONDAY THROUGH FRIDAY/
Short Term...No change in the weather pattern. Fog will bring restrictions through early this morning, mainly at LEB, HIE, and RKD, and then VFR the rest of today. The same sites will likely see fog again tonight and possibly AUG, but then VFR returns the remainder of Tuesday.
Long Term...VFR conditions look to prevail, but there will be the chance for some restrictions due to coastal and valley fog.
This appears most likely during the overnight and early morning hours. Weak winds in the low levels present little risk of LLWS development, with wind shifts expected around daily sea breeze fronts.
MARINE
Short Term...Conditions remain below SCA levels across the waters with prevailing south to southwest winds through Tuesday, backing to the S/SSE and increasing slightly in the afternoons with the seabreeze.
Seas over the outer waters will run 2-3 ft, occasionally up to 4 ft today. Fog/stratus will also be possible, especially across the eastern waters and near Penobscot Bay.
Long Term...High pressure centered to the south will keep conditions over the waters below SCA criteria. Expect some marine stratus/fog to develop in warming air temperatures this week. Onshore flow directions expected for the most part, with diurnal sea breeze. Wave heights generally remain 2 to 3 ft.
CLIMATE
Daily record highs and year(s) set for today, August 11 through Wednesday, August 13 for Portland, Augusta, and Concord.
Portland Augusta Concord Aug 11 99F (1944) 94F (2016) 98F (2016, 1944)
Aug 12 99F (2016, 1944) 93F (2002) 99F (2016, 1944)
Aug 13 99F (1947) 94F (2004) 99F (1944)
GYX WATCHES/WARNINGS/ADVISORIES
ME...Heat Advisory from 11 AM this morning to 8 PM EDT Tuesday for MEZ012>014-018>022-033.
NH...Heat Advisory from 11 AM this morning to 8 PM EDT Tuesday for NHZ010-012-013.
MARINE...None.
Area Forecast Discussion National Weather Service Gray ME 357 AM EDT Mon Aug 11 2025
SYNOPSIS
High pressure remains in control for the next few days, and temperatures continue to rise through the first half of this week as a ridge of high pressure builds over the Northeast. The ridge starts to break down mid week and that will allow for some chances of showers and thunderstorms as a cold front approaches. The weekend looks to be dry at this time with a warming trend possible by Sunday.
NEAR TERM /UNTIL 6 PM THIS EVENING/
355AM Update...Just resending to add a climate section as forecast temperatures could threaten daily record highs today through Wednesday.
Previous...
There will be patchy fog in some areas this morning, especiallthreateny within river valleys, but once this clears by 8 to 9 AM, the focus remains on the heat with temperatures expected to climb even higher than yesterday. A strong ridge of high pressure builds directly overhead today bringing mostly sunny, hot and dry conditions. 850mb temps of +18C to +20c supports highs reaching the lower to mid 90s across much of the interior today with heat indices likely above 95F for a few hours this afternoon across the Maine interior/foothills stretching into southeastern NH, where the Heat Advisory is in place. Looking back at the past few days, NBM and MAV guidance have had consistent a cool bias away from the coast, possibly due to how dry it is. So I've played the persistence card on temps today by going a degree or so above the NBM, but this doesn't really change the overall message of it's going to be hot regardless. A little more moisture toward the mountains may result in a shower or two this afternoon but mainly just a tad more in the way of clouds than southern areas.
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/
Fortunately there will be some relief to the heat tonight.
Mostly clear skies and light winds will allow for radiational cooling, and since the airmass is not as humid as past heat events this summer, temperatures will be able to reach the low to middle 60s for lows, possibly even the upper 50s in some of the northern valleys. Speaking of valleys, valley fog will probably develop in many areas and possibly the Augusta and Midcoast regions as well.
The synoptic patterns remains largely unchanged with strong ridge of high pressure remaining directly overhead for Tuesday, bringing nearly identical conditions to those of today: hot and mostly sunny with only a very low chance of a shower or two in the mountains. Temperatures away from the coast are expected to reach the low to mid 90s, possibly even upper 90s in some spots, with heat index values likely exceeding 95F for a few hours in many areas, where the Heat Advisory remains. Those not in the Heat Advisory can still expected heat indices in the 90-95F range, even closer to the coast before the seabreeze moves ashore in the afternoon.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/
Early morning long-term update...
Key messages from the previous shift remain the same through Wednesday as another hot day is expected. There's a good chance that the heat advisory will have to be extended for Wednesday.
The same holds with precipitation chances as the best chance for at least widely scattered showers and thunderstorms looks to be during the afternoons Wed and Thu. Widespread rains are not expected however.
Previously...
Key Messages: * Heat continues Wednesday with highs in the upper 80s to mid 90s. A Heat Advisory with continuation into Wednesday likely.
* Cold front approaches Wednesday, decreasing temperatures late week.
Details: Continued to increase temperatures Wednesday from the NBM deterministic. Combination of dry surface conditions and mostly sunny skies should allow for quick morning warmup to around 90 for much of the forecast area. From here, highs push into the low to mid 90s across the interior and even mtn valleys. Along the coast (especially the Midcoast), light onshore flow will tend to strengthen in the afternoon, reinforced by seabreeze. Thus, temps along the coast peak early afternoon, with a moderating airmass for remainder of the day.
The good news, despite this longer period of heat, is the relative dryness of the airmass as well as good overnight recovery temperatures in the 60s. Dewpoint temps will tend to run low considering dry antecedent surface conditions, but there won't be enough momentum transfer to mix down even drier values.
This keeps heat index values close to actual temperatures.
Given the confidence in this airmass, an extension to the Heat Advisory will likely be needed for Wednesday, but next incoming cold front offers some uncertainty in cloud cover and possible showers.
Consensus does keep precipitation largely west of the CWA into early Wed afternoon, but can expect some clouds ahead. With building CAPE and forcing, could see some showers and thunderstorms develop ahead of the main forcing. However, lapse rates are not steep and shear of around 20 kts could prevent a more widespread thunder event.
Winds shift NW behind the front Thursday, with a dip in expected high temperatures late week into the mid to lower 80s.
AVIATION /08Z MONDAY THROUGH FRIDAY/
Short Term...No change in the weather pattern. Fog will bring restrictions through early this morning, mainly at LEB, HIE, and RKD, and then VFR the rest of today. The same sites will likely see fog again tonight and possibly AUG, but then VFR returns the remainder of Tuesday.
Long Term...VFR conditions look to prevail, but there will be the chance for some restrictions due to coastal and valley fog.
This appears most likely during the overnight and early morning hours. Weak winds in the low levels present little risk of LLWS development, with wind shifts expected around daily sea breeze fronts.
MARINE
Short Term...Conditions remain below SCA levels across the waters with prevailing south to southwest winds through Tuesday, backing to the S/SSE and increasing slightly in the afternoons with the seabreeze.
Seas over the outer waters will run 2-3 ft, occasionally up to 4 ft today. Fog/stratus will also be possible, especially across the eastern waters and near Penobscot Bay.
Long Term...High pressure centered to the south will keep conditions over the waters below SCA criteria. Expect some marine stratus/fog to develop in warming air temperatures this week. Onshore flow directions expected for the most part, with diurnal sea breeze. Wave heights generally remain 2 to 3 ft.
CLIMATE
Daily record highs and year(s) set for today, August 11 through Wednesday, August 13 for Portland, Augusta, and Concord.
Portland Augusta Concord Aug 11 99F (1944) 94F (2016) 98F (2016, 1944)
Aug 12 99F (2016, 1944) 93F (2002) 99F (2016, 1944)
Aug 13 99F (1947) 94F (2004) 99F (1944)
GYX WATCHES/WARNINGS/ADVISORIES
ME...Heat Advisory from 11 AM this morning to 8 PM EDT Tuesday for MEZ012>014-018>022-033.
NH...Heat Advisory from 11 AM this morning to 8 PM EDT Tuesday for NHZ010-012-013.
MARINE...None.
| Stations | Dist | Age | Wind | Air | Water | Waves | inHg | DewPt |
| CASM1 - 8418150 - Portland, ME | 23 mi | 56 min | ESE 5.1G | 73°F | 61°F | 30.12 | ||
| 44007 - PORTLAND 12 NM Southeast of Portland,ME | 28 mi | 46 min | S 3.9G | 71°F | 68°F | 30.14 | 67°F | |
| 44032 - Buoy E0104 - Central Maine Shelf | 35 mi | 116 min | 4 ft |
Wind History for Portland, ME
toggle option: (graph/table)
Link to 1 hour of 5 minute data for KIWI
Terminal Aerodrome Forecast (TAF) for KIWI
Wind History Graph: IWI
(wind in knots)
GEOS Local Image of north east
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Portland, ME,
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