Norwalk climate

Norwalk Weather in September

NOAA 1991-2020 normals for Stamford 5 N, 11.7 km from Norwalk

Average highs run from 80°F on September 1 to 70°F on September 30, and lows from 61°F to 51°F. Normal precipitation for the month is 5.21 in over about 9 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 Norwalk, in °F, with the record for each date.20406080100151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

September at a glance

Average high
76°F
Average low
56°F
Precipitation
5.21 in
Record high
99°FSep 2, 1953
Record low
36°FSep 21, 1956
Chance of a freeze
0%
Days of 90°F or more
1.0
Daylight
13 h 06 min to 11 h 48 min
Cloud cover
55%
Humidity
74%
Dew point
57°F
Wind
6.3 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 180°F61°F93°F 201052°F 197027%0%
Sep 280°F61°F99°F 195350°F 194927%0%
Sep 380°F60°F91°F 199346°F 196727%0%
Sep 480°F60°F91°F 197351°F 199727%0%
Sep 579°F60°F91°F 196149°F 198227%0%
Sep 679°F60°F92°F 198348°F 198427%0%
Sep 779°F59°F93°F 202346°F 196227%0%
Sep 878°F59°F94°F 201549°F 196227%0%
Sep 978°F59°F90°F 201648°F 195627%0%
Sep 1078°F58°F93°F 198346°F 195627%0%
Sep 1178°F58°F90°F 198345°F 196928%0%
Sep 1277°F58°F88°F 195244°F 195828%0%
Sep 1377°F57°F89°F 195246°F 195428%0%
Sep 1476°F57°F88°F 201644°F 196328%0%
Sep 1576°F57°F85°F 199346°F 196329%0%
Sep 1676°F56°F89°F 199143°F 196429%0%
Sep 1775°F56°F89°F 199141°F 195029%0%
Sep 1875°F56°F84°F 199242°F 199030%0%
Sep 1975°F55°F88°F 198342°F 195930%0%
Sep 2074°F55°F87°F 198342°F 197930%0%
Sep 2174°F54°F85°F 196536°F 195631%0%
Sep 2273°F54°F89°F 197042°F 196231%0%
Sep 2373°F54°F91°F 197040°F 196331%0%
Sep 2473°F53°F87°F 195936°F 196332%0%
Sep 2572°F53°F85°F 197037°F 195032%0%
Sep 2672°F52°F84°F 195843°F 194932%0%
Sep 2772°F52°F84°F 199837°F 195733%0%
Sep 2871°F52°F81°F 195936°F 195733%0%
Sep 2971°F51°F83°F 195939°F 195733%0%
Sep 3070°F51°F82°F 198637°F 195133%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Norwalk, 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 6:20 AM, sunset 7:26 PM
September 30
sunrise 6:49 AM, sunset 6:37 PM

Every day of September: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00067970 (Stamford 5 N), public domain. Records: NOAA GHCN-Daily, station USW00094702, 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.