Marine Weather and Tide Forecast for Harwich Port, MA
 | Sunrise 7:06 AM Sunset 5:43 PM Moonrise 5:40 PM Moonset 7:42 AM |
Marine Forecasts
NOTE: Zones updated 4/16/2026. Some zones changed. Use Edit if needed.
ANZ232 Nantucket Sound- 1003 Pm Edt Mon Oct 26 2026
.small craft advisory in effect from 2 am edt Tuesday through Tuesday morning - .
Overnight - NW winds around 10 kt, becoming N 15 to 20 kt. Gusts up to 25 kt. Seas 2 to 3 ft. Wave detail: W 2 ft at 3 seconds and E 2 ft at 9 seconds.
Tue - N winds 15 to 20 kt, diminishing to 10 to 15 kt in the afternoon. Gusts up to 25 kt. Seas 2 to 3 ft. Wave detail: ne 3 ft at 4 seconds and W 2 ft at 5 seconds.
Tue night - NE winds 5 to 10 kt, becoming N after midnight. Seas around 2 ft. Wave detail: ne 2 ft at 7 seconds and nw 1 foot at 4 seconds.
Wed - N winds around 5 kt, becoming S in the afternoon. Seas around 2 ft. Wave detail: nw 1 foot at 5 seconds and E 1 foot at 8 seconds.
Wed night through Thu night - SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave detail: sw 2 ft at 3 seconds and E 1 foot at 7 seconds.
Fri through Sat night - SE winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave detail: sw 2 ft at 4 seconds and se 1 foot at 8 seconds.
seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height.
seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height.
ANZ200 1003 Pm Edt Mon Oct 26 2026
Synopsis for massachusetts and rhode island coastal waters - High pressure centered south of new england across the mid-atlantic brings dry weather and generally favorable marine conditions today. A moisture-starved cold front crosses the southern new england waters tonight into early Tuesday, bringing gusty northerly winds. High pressure builds back across the waters Tuesday night into Wednesday, then shifts offshore Thursday, allowing winds to turn southwesterly. Another cold front approaches from the northwest Friday, potentially crossing the waters Friday night.
7 Day Forecast for Marine Location Near Harwich Port, MA
NEW! Add second zone forecast
| Dennisport Click for Map Mon -- 12:13 AM EDT Full Moon Mon -- 12:27 AM EDT 3.65 feet High Tide Mon -- 06:07 AM EDT 0.02 feet Low Tide Mon -- 07:05 AM EDT Sunrise Mon -- 07:41 AM EDT Moonset Mon -- 12:40 PM EDT 4.04 feet High Tide Mon -- 05:39 PM EDT Moonrise Mon -- 05:42 PM EDT Sunset Mon -- 06:40 PM EDT -0.31 feet Low Tide Tide / Current data from XTide NOT FOR NAVIGATION |
Dennisport, Nantucket Sound, Massachusetts, Tide feet
| 12 am |
| 3.6 |
| 1 am |
| 3.6 |
| 2 am |
| 3.1 |
| 3 am |
| 2.2 |
| 4 am |
| 1.3 |
| 5 am |
| 0.4 |
| 6 am |
| 0 |
| 7 am |
| 0.2 |
| 8 am |
| 0.9 |
| 9 am |
| 1.7 |
| 10 am |
| 2.6 |
| 11 am |
| 3.4 |
| 12 pm |
| 3.9 |
| 1 pm |
| 4 |
| 2 pm |
| 3.6 |
| 3 pm |
| 2.7 |
| 4 pm |
| 1.6 |
| 5 pm |
| 0.6 |
| 6 pm |
| -0.2 |
| 7 pm |
| -0.3 |
| 8 pm |
| 0.1 |
| 9 pm |
| 0.9 |
| 10 pm |
| 1.8 |
| 11 pm |
| 2.6 |
| Monomoy Pt. Click for Map Flood direction 170 true Ebb direction 346 true Mon -- 12:13 AM EDT Full Moon Mon -- 03:25 AM EDT 0.00 knots Slack Mon -- 07:04 AM EDT Sunrise Mon -- 07:17 AM EDT 1.72 knots Max Flood Mon -- 07:41 AM EDT Moonset Mon -- 10:11 AM EDT -0.00 knots Slack Mon -- 12:13 PM EDT -2.48 knots Max Ebb Mon -- 03:42 PM EDT 0.00 knots Slack Mon -- 05:39 PM EDT Moonrise Mon -- 05:42 PM EDT Sunset Mon -- 07:37 PM EDT 1.84 knots Max Flood Mon -- 10:38 PM EDT -0.00 knots Slack Tide / Current data from XTide NOT FOR NAVIGATION |
Monomoy Pt., channel 0.2 mi west of, Nantucket Sound, Massachusetts Current, knots
| 12 am |
| -2.4 |
| 1 am |
| -2.1 |
| 2 am |
| -1.4 |
| 3 am |
| -0.5 |
| 4 am |
| 0.4 |
| 5 am |
| 1.1 |
| 6 am |
| 1.5 |
| 7 am |
| 1.7 |
| 8 am |
| 1.6 |
| 9 am |
| 1.1 |
| 10 am |
| 0.2 |
| 11 am |
| -1.5 |
| 12 pm |
| -2.5 |
| 1 pm |
| -2.3 |
| 2 pm |
| -1.7 |
| 3 pm |
| -0.8 |
| 4 pm |
| 0.2 |
| 5 pm |
| 0.9 |
| 6 pm |
| 1.5 |
| 7 pm |
| 1.8 |
| 8 pm |
| 1.8 |
| 9 pm |
| 1.4 |
| 10 pm |
| 0.7 |
| 11 pm |
| -0.7 |
FXUS61 KBOX 262300 AFDBOX
Area Forecast Discussion National Weather Service Boston/Norton MA 700 PM EDT Mon Oct 26 2026
WHAT HAS CHANGED
No meaningful changes to the forecast, with an extended stretch of quiet and dry weather ahead.
KEY MESSAGES
- Prolonged stretch of dry weather through the first half of the upcoming weekend. Seasonably cool temperatures Tuesday through midweek followed by period of warmer temperatures later in the work week.
DISCUSSION
KEY MESSAGE 1...Prolonged stretch of dry weather through the first half of the upcoming weekend. Seasonably cool temperatures Tuesday through midweek followed by period of warmer temperatures later in the work week.
A cold front pushes southward into southern New England tonight.
This front will be fairly moisture-starved limiting it's impacts to a period of breezy northerly winds overnight accompanied by advection of a cooler airmass.
Upper ridging and surface high pressure will dominate through the upcoming weekend favoring dry weather. Southern New England will be in a cooler post-frontal airmass Tuesday with 925mb temperatures ranging +1C to +4C. This will support high temperatures in the mid to upper 50s. Locations along the Cape/Islands and even portions of the east coast may be limited to the low 50s given the N/NNE onshore wind component. The cool airmass in place combined with light winds and clear skies will favor efficient radiational cooling Tuesday night into Wednesday. Temperatures are likely to fall into the upper 20s and 30s. The higher terrain, valleys, and other radiator spots have potential to see mid 20s with even a some spots in the low 20s!
Similar conditions prevail Wednesday. Temperatures trend slightly warmer as a mid level ridge shifts further east into the region accompanied by warmer temperatures aloft. The warming trend in temperatures continues into late-week resulting in 925mb temperatures warming to +10 to +13C. This will yield high temperatures in the mid-60s on Thursday which is seasonably warm for this time of year. Despite the mid-level pattern becoming more zonal Friday (ahead of our next weak wave), the westerly flow will support efficient mixing in the boundary. This will result in a breezy, but likely the warmest day of the week with high temperatures in the upper 60s and even low 70s in portions of southern New England. NBM highlights moderate to high probabilities(60%-80%+) for 70F or greater across the valleys, CT, and I-95 corridor. Therefore a larger portion of southern New England, with the exception of the higher elevations and Cape/Islands, will have a good shot at hitting the 70 degree mark on Friday.
Another moisture-starved shortwave and cold front moves overnight Friday. This will bring back temperatures into the low 60s for the weekend which is seasonable for late-October. Looking further ahead to the latter half of the weekend and next week, ensemble guidance shows agreement with a transition to a generally unsettled pattern which may feature periodic chances for showers. Confidence decreases with respect to the details such as timing.
AVIATION /00Z TUESDAY THROUGH SATURDAY/
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
00Z TAF Update:
Today and Tonight...High confidence.
VFR conditions. W winds turn NW with occasional gusts of 18-25 kts as a cold front pushes through the region between 00-04Z.
Highest gusts for Cape and Islands. SCT to BKN cloud decks accompany the front, but likely to be mid- level (050-100).
Tuesday...High confidence.
VFR. Gusts subside by 12Z for most terminals while Cape/Island terminals will see lingering gusts through early afternoon.
Winds N/NNE at 7-14 kts.
KBOS Terminal...High confidence.
KBDL Terminal...High confidence.
Outlook /Tuesday Night through Saturday/...
Wednesday through Wednesday Night: VFR.
Thursday through Thursday Night: VFR. Breezy.
Friday through Saturday: VFR.
MARINE
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Through Tuesday...High confidence.
A moisture-starved cold front pushes across the coastal waters 00-04Z bringing a wind shift to the N with a period of gusts around 25 kts across the eastern and southeastern waters. Gusts decrease to less than 25 kts by 12Z Tuesday. Seas build to 3 to 5 ft across the outer waters tonight into Tuesday. As a result, Small Craft Advisories in effect tonight into Tuesday for the aforementioned waters. It is possible 5 ft seas may linger along the outermost borders of the outer water zones Tuesday.
Outlook /Tuesday Night through Saturday/...
Wednesday through Thursday: Winds less than 25 kt.
Thursday Night through Saturday: Winds less than 25 kt. Seas locally approaching 5 ft.
BOX WATCHES/WARNINGS/ADVISORIES
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory from 2 AM to 11 AM EDT Tuesday for ANZ231- 232-250-251-254-255.
Area Forecast Discussion National Weather Service Boston/Norton MA 700 PM EDT Mon Oct 26 2026
WHAT HAS CHANGED
No meaningful changes to the forecast, with an extended stretch of quiet and dry weather ahead.
KEY MESSAGES
- Prolonged stretch of dry weather through the first half of the upcoming weekend. Seasonably cool temperatures Tuesday through midweek followed by period of warmer temperatures later in the work week.
DISCUSSION
KEY MESSAGE 1...Prolonged stretch of dry weather through the first half of the upcoming weekend. Seasonably cool temperatures Tuesday through midweek followed by period of warmer temperatures later in the work week.
A cold front pushes southward into southern New England tonight.
This front will be fairly moisture-starved limiting it's impacts to a period of breezy northerly winds overnight accompanied by advection of a cooler airmass.
Upper ridging and surface high pressure will dominate through the upcoming weekend favoring dry weather. Southern New England will be in a cooler post-frontal airmass Tuesday with 925mb temperatures ranging +1C to +4C. This will support high temperatures in the mid to upper 50s. Locations along the Cape/Islands and even portions of the east coast may be limited to the low 50s given the N/NNE onshore wind component. The cool airmass in place combined with light winds and clear skies will favor efficient radiational cooling Tuesday night into Wednesday. Temperatures are likely to fall into the upper 20s and 30s. The higher terrain, valleys, and other radiator spots have potential to see mid 20s with even a some spots in the low 20s!
Similar conditions prevail Wednesday. Temperatures trend slightly warmer as a mid level ridge shifts further east into the region accompanied by warmer temperatures aloft. The warming trend in temperatures continues into late-week resulting in 925mb temperatures warming to +10 to +13C. This will yield high temperatures in the mid-60s on Thursday which is seasonably warm for this time of year. Despite the mid-level pattern becoming more zonal Friday (ahead of our next weak wave), the westerly flow will support efficient mixing in the boundary. This will result in a breezy, but likely the warmest day of the week with high temperatures in the upper 60s and even low 70s in portions of southern New England. NBM highlights moderate to high probabilities(60%-80%+) for 70F or greater across the valleys, CT, and I-95 corridor. Therefore a larger portion of southern New England, with the exception of the higher elevations and Cape/Islands, will have a good shot at hitting the 70 degree mark on Friday.
Another moisture-starved shortwave and cold front moves overnight Friday. This will bring back temperatures into the low 60s for the weekend which is seasonable for late-October. Looking further ahead to the latter half of the weekend and next week, ensemble guidance shows agreement with a transition to a generally unsettled pattern which may feature periodic chances for showers. Confidence decreases with respect to the details such as timing.
AVIATION /00Z TUESDAY THROUGH SATURDAY/
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
00Z TAF Update:
Today and Tonight...High confidence.
VFR conditions. W winds turn NW with occasional gusts of 18-25 kts as a cold front pushes through the region between 00-04Z.
Highest gusts for Cape and Islands. SCT to BKN cloud decks accompany the front, but likely to be mid- level (050-100).
Tuesday...High confidence.
VFR. Gusts subside by 12Z for most terminals while Cape/Island terminals will see lingering gusts through early afternoon.
Winds N/NNE at 7-14 kts.
KBOS Terminal...High confidence.
KBDL Terminal...High confidence.
Outlook /Tuesday Night through Saturday/...
Wednesday through Wednesday Night: VFR.
Thursday through Thursday Night: VFR. Breezy.
Friday through Saturday: VFR.
MARINE
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Through Tuesday...High confidence.
A moisture-starved cold front pushes across the coastal waters 00-04Z bringing a wind shift to the N with a period of gusts around 25 kts across the eastern and southeastern waters. Gusts decrease to less than 25 kts by 12Z Tuesday. Seas build to 3 to 5 ft across the outer waters tonight into Tuesday. As a result, Small Craft Advisories in effect tonight into Tuesday for the aforementioned waters. It is possible 5 ft seas may linger along the outermost borders of the outer water zones Tuesday.
Outlook /Tuesday Night through Saturday/...
Wednesday through Thursday: Winds less than 25 kt.
Thursday Night through Saturday: Winds less than 25 kt. Seas locally approaching 5 ft.
BOX WATCHES/WARNINGS/ADVISORIES
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory from 2 AM to 11 AM EDT Tuesday for ANZ231- 232-250-251-254-255.
| Stations | Dist | Age | Wind | Air | Water | Waves | inHg | DewPt |
| 44020 - NANTUCKET SOUND | 13 mi | 30 min | W 9.7G | 59°F | 56°F | 30.05 | ||
| NTKM3 - 8449130 - Nantucket Island, MA | 20 mi | 52 min | W 6G | 56°F | 30.08 | |||
| 44090 | 24 mi | 100 min | 61°F | 57°F | 1 ft | |||
| WAXM3 - Waquoit Bay Reserve, MA | 25 mi | 70 min | 0 | 52°F | 30.06 | 51°F | ||
| BZBM3 - 8447930 - Woods Hole, MA | 33 mi | 52 min | 58°F | 30.08 | ||||
| NBGM3 | 46 mi | 52 min | NW 11G | 30.09 |
Wind History for Nantucket Island, MA
toggle option: (graph/table)
Link to 5 hour of 5 minute data for KCQX
Terminal Aerodrome Forecast (TAF) for KCQX
Wind History Graph: CQX
(wind in knots)
GEOS Local Image of north east
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