Grand Isle County climate

Grand Isle County Weather in September

NOAA 1991-2020 normals for St Albans Radio, 17.5 km from Grand Isle County

Average highs run from 75°F on September 1 to 63°F on September 30, and lows from 56°F to 46°F. Normal precipitation for the month is 3.93 in over about 10 wet days.

September day by day

The normal high and low for each date, and the record, in °F.

Normal daily high and low temperature at Grand Isle County, in °F, with the record for each date.20406080100151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

September at a glance

Average high
69°F
Average low
51°F
Precipitation
3.93 in
Record high
94°FSep 3, 2018
Record low
28°FSep 21, 2020
Chance of a freeze
15%
Daylight
13 h 14 min to 11 h 45 min
Cloud cover
59%
Humidity
74%
Dew point
51°F
Wind
4.7 mph

Every day of the month

A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.

DateNormal highNormal lowRecord highRecord lowChance wetChance of snow
Sep 175°F56°F89°F 201043°F 200932%0%
Sep 274°F56°F90°F 201041°F 201732%0%
Sep 374°F55°F94°F 201841°F 201732%0%
Sep 474°F55°F84°F 201148°F 202533%0%
Sep 573°F55°F90°F 201845°F 200733%0%
Sep 673°F54°F87°F 202339°F 201333%0%
Sep 773°F54°F93°F 201545°F 200933%0%
Sep 873°F54°F91°F 200744°F 201333%0%
Sep 972°F53°F90°F 201539°F 201333%0%
Sep 1072°F53°F84°F 201642°F 201833%0%
Sep 1171°F53°F93°F 201337°F 200833%0%
Sep 1271°F52°F83°F 201137°F 202034%0%
Sep 1371°F52°F84°F 201637°F 201434%
Sep 1470°F52°F84°F 202438°F 201434%
Sep 1570°F51°F83°F 200834°F 201434%
Sep 1670°F51°F83°F 202437°F 200735%
Sep 1769°F51°F84°F 201835°F 200735%
Sep 1869°F50°F82°F 201535°F 202035%
Sep 1968°F50°F83°F 201530°F 201435%
Sep 2068°F50°F86°F 201631°F 202035%
Sep 2167°F49°F84°F 201628°F 202036%
Sep 2267°F49°F85°F 200730°F 202036%
Sep 2367°F48°F82°F 202132°F 200836%
Sep 2466°F48°F86°F 201739°F 201236%
Sep 2566°F48°F91°F 200737°F 201236%
Sep 2665°F47°F85°F 200733°F 200936%
Sep 2765°F47°F89°F 201735°F 201537%
Sep 2864°F46°F79°F 202536°F 201237%
Sep 2964°F46°F82°F 202537°F 202237%
Sep 3063°F46°F72°F 202433°F 202237%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Grand Isle County, in percent, and of at least 0.1 inch of snowfall.0102030401102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (EDT).

September 1
sunrise 6:16 AM, sunset 7:30 PM
September 30
sunrise 6:50 AM, sunset 6:35 PM

Every day of September: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00437032 (St Albans Radio), public domain. Records: NOAA GHCN-Daily, station USW00064776, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.