Stonington climate

Stonington Weather in September

NOAA 1991-2020 normals for Decatur Wtp, 29.5 km from Stonington

Average highs run from 82°F on September 1 to 73°F on September 30, and lows from 62°F to 52°F. Normal precipitation for the month is 3.08 in over about 8 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 Stonington, in °F, with the record for each date.20406080100120151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

September at a glance

Average high
78°F
Average low
57°F
Precipitation
3.08 in
Record high
105°FSep 3, 2026
Record low
29°FSep 23, 1983
Chance of a freeze
2%
Days of 90°F or more
3.3
Daylight
13 h 03 min to 11 h 49 min
Cloud cover
46%
Humidity
69%
Dew point
56°F
Wind
8.3 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 182°F62°F99°F 202644°F 198725%0%
Sep 282°F62°F104°F 202643°F 201725%0%
Sep 381°F62°F105°F 202644°F 201725%0%
Sep 481°F61°F104°F 202640°F 198426%0%
Sep 581°F61°F104°F 202643°F 198426%0%
Sep 681°F61°F104°F 202638°F 198826%0%
Sep 780°F60°F97°F 199039°F 198826%0%
Sep 880°F60°F93°F 199035°F 198626%0%
Sep 980°F60°F98°F 202641°F 202526%0%
Sep 1080°F59°F97°F 201343°F 199926%0%
Sep 1179°F59°F98°F 198342°F 199226%0%
Sep 1279°F58°F97°F 202642°F 200726%0%
Sep 1379°F58°F93°F 200539°F 201426%0%
Sep 1479°F58°F99°F 202536°F 201426%0%
Sep 1578°F57°F100°F 202534°F 200726%0%
Sep 1678°F57°F94°F 202538°F 198426%0%
Sep 1778°F57°F104°F 202640°F 198426%0%
Sep 1877°F56°F95°F 202437°F 198126%0%
Sep 1977°F56°F96°F 202535°F 199126%0%
Sep 2077°F55°F95°F 200532°F 199127%0%
Sep 2176°F55°F96°F 202233°F 199127%0%
Sep 2276°F55°F95°F 201731°F 198327%0%
Sep 2375°F54°F96°F 200529°F 198327%0%
Sep 2475°F54°F94°F 200732°F 199527%0%
Sep 2575°F53°F95°F 201734°F 199527%0%
Sep 2674°F53°F94°F 201735°F 198927%0%
Sep 2774°F53°F94°F 201733°F 198527%0%
Sep 2873°F52°F93°F 199836°F 202227%0%
Sep 2973°F52°F93°F 198633°F 200327%0%
Sep 3073°F52°F90°F 202531°F 198427%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Stonington, in percent, and of at least 0.1 inch of snowfall.01020301102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (CDT).

September 1
sunrise 6:25 AM, sunset 7:28 PM
September 30
sunrise 6:52 AM, sunset 6:41 PM

Every day of September: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00112193 (Decatur Wtp), public domain. Records: NOAA GHCN-Daily, station USC00115841, 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.