Climate averages 1991–2020
Stamford weather
in September.
A warm, wet month: the 4th warmest and the joint 7th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a warm month in Stamford: daytime highs average 23.2°C and nights cool to about 16.4°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 94 mm of rain on roughly 9 days, which makes September a wet month (the joint 7th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 31 min on an average September day.
The nearest other city in this atlas is Norwalk (13 km away). In September its highs average 23.1°C, about as warm as Stamford, with 94 mm of rain.
Among the 498 cities listed in the United States, Stamford ranks joint 393rd of 498 for the warmest September highs and joint 365th of 498 for the driest September (rainfall, lowest first). The mean September high of those 498 cities is 26.9°C; Stamford is 3.7°C cooler than that mean.
From September to October, average highs fall by 6.4°C to 16.8°C, and monthly rainfall rises from 94 mm to 100 mm.
The annual picture
September in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Stamford climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 2.7°C-4.2°C | -4.2°C | 84 | 9.0 | 9.610 h |
| February | 3.9°C-3.8°C | -3.8°C | 78 | 8.7 | 10.611 h |
| March | 8.0°C-0.1°C | -0.1°C | 105 | 10.3 | 11.912 h |
| April | 14.3°C5.5°C | 5.5°C | 93 | 10.5 | 13.313 h |
| May | 19.8°C11.3°C | 11.3°C | 85 | 10.9 | 14.514 h |
| June | 25.0°C17.0°C | 17.0°C | 94 | 10.8 | 15.115 h |
| July | 28.3°C20.5°C | 20.5°C | 92 | 10.7 | 14.815 h |
| August | 27.2°C19.9°C | 19.9°C | 103 | 10.5 | 13.814 h |
| September, selected | 23.2°C16.4°C | 16.4°C | 94 | 9.0 | 12.513 h |
| October | 16.8°C10.4°C | 10.4°C | 100 | 8.5 | 11.111 h |
| November | 10.8°C4.7°C | 4.7°C | 82 | 8.5 | 9.910 h |
| December | 5.5°C-0.3°C | -0.3°C | 105 | 9.8 | 9.39 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Norwalk in SeptemberUnited States · 13 kmHigh 23.1°C · Low 16.4°C · 94 mm rain
- Greenburgh in SeptemberUnited States · 26 kmHigh 23.3°C · Low 15.9°C · 95 mm rain
- Bridgeport in SeptemberUnited States · 32 kmHigh 22.8°C · Low 16.4°C · 103 mm rain
- Yonkers in SeptemberUnited States · 33 kmHigh 23.7°C · Low 15.8°C · 101 mm rain
- The Bronx in SeptemberUnited States · 36 kmHigh 23.8°C · Low 15.7°C · 92 mm rain
- Danbury in SeptemberUnited States · 39 kmHigh 23.0°C · Low 14.6°C · 108 mm rain
- Manhattan in SeptemberUnited States · 47 kmHigh 23.7°C · Low 15.6°C · 94 mm rain
- Queens in SeptemberUnited States · 48 kmHigh 23.6°C · Low 16.5°C · 92 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Stamford) is explained once on the Stamford year overview and on the Sources, method and limits page.
Norwalk lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.