Dangerous Heat and Humidity Building from the Plains to the East Coast

A strengthening ridge of high pressure will produce much above average temperatures from the Plains to the East Coast, a true summer heat wave. Highs in the 90s and triple digits combined w/ humidity and dewpoints surging into the upper 70s, if not low 80s, will create heat indices as high as 110 to 115 through this weekend. Air quality will likely be poor due to haze and little air circulation.

Hazardous Weather Conditions

For More Weather Information:

Gray/Portland, ME Local Forecast Office

9NM ESE Portsmouth NH

Marine Point Forecast

  • Today

    Mostly Cloudy

    ENE 15kt

    High: 69 °F

  • Tonight

    Mostly Cloudy

    ENE 10kt

    Low: 63 °F

  • Friday

    Partly Sunny

    Winds IncreasingS 10kt

    High: 80 °F

  • Friday

    Areas Fog

    S 10kt

    Low: 73 °F

  • Saturday

    Areas Fog

    WSW 10kt

    High: 86 °F

  • Saturday

    Partly Cloudy

    WSW 10kt

    Low: 75 °F

  • Sunday

    Chance Thunderstorms

    SW 10kt

    High: 82 °F

  • Sunday

    Mostly Cloudy

    W 10kt

    Low: 71 °F

  • Monday

    Chance Showers

    Light Wind

    High: 77 °F

High and low forecast temperature values represent air temperature.

Associated Zone Forecast which includes this point

Last Update: 6:03 am EDT Jul 18, 2019
Forecast Valid: 9am EDT Jul 18, 2019-6pm EDT Jul 24, 2019

View Nearby Observations

Detailed Forecast

Synopsis: ANZ100-182145- 342 AM EDT Thu Jul 18 2019 .Synopsis for Stonington ME to Merrimack River MA out to 25 NM... A cold front will stall over southern New England today as high pressure builds in from the north. High pressure will slide off to the east this afternoon. A warm front will lift northeast through the region Friday into Saturday morning. A cold front will approach from the north on Saturday and will slowly drop south through Sunday and Sunday night with an additional frontal passage on its heels. High pressure will gradually build in from the west Monday through Tuesday. && $$

ENE wind 10 to 15 kt. Mostly cloudy. Seas 3 to 4 ft.
ENE wind 5 to 10 kt becoming N after midnight. Mostly cloudy. Seas 2 to 3 ft.
E wind 5 to 8 kt becoming S 7 to 10 kt in the morning. Partly sunny. Seas around 2 ft.
Friday Night
S wind around 10 kt becoming WSW after midnight. Areas of fog after 2am. Seas around 2 ft.
W wind around 10 kt becoming SW in the afternoon. Areas of fog before 8am. Seas 1 to 2 ft.
Saturday Night
WSW wind around 10 kt. Partly cloudy. Seas around 1 ft.
W wind 5 to 10 kt becoming S in the afternoon. A chance of showers and thunderstorms. Seas around 1 ft.
Sunday Night
W wind 5 to 10 kt. Mostly cloudy. Seas 1 to 2 ft.
Variable winds 5 kt or less. A chance of showers. Seas around 1 ft.

Winds and seas higher in and near tstms.


  1. This forecast is for a single location. For safety concerns, mariners should be aware of the weather over a larger area. Forecast information for a larger area can be found within the zone forecast and the NDFD graphics.
  2. The forecast conditions at a particular point may not exceed the criteria of a Small Craft Advisory, Gale, Storm etc. These watches/warnings/advisories are issued for the entire zone in which the point resides and mariners should act accordingly.
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Point Forecast: 42.99°N 70.62°W
Last Update: 6:03 am EDT Jul 18, 2019
Forecast Valid: 9am EDT Jul 18, 2019-6pm EDT Jul 24, 2019
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