Connecticut, USA
Long term weather forecast
Long term weather forecast

September weather forecast and Climate
Hartford, CT

  • Average high temperature in September: 23.8°C

Warmest month (with highest average high temperature) is July (29.2°C).
Month with lowest average high temperature is January (1.4°C).

  • Average low temperature in September: 11.5°C

Month with highest average low temperature is July (17.1°C).
Coldest month (with lowest average low temperature) is January (-7.9°C).

  • Average humidity in September: 72.9%

Month with highest relative humidity is September (72.9%).
Month with lowest relative humidity is April (58%).

  • Average rainfall in September: 98.6mm

Wettest month (with highest rainfall) is October (111mm).
Driest month (with lowest rainfall) is February (73.4mm).

  • Average rainfall days in September: 9.8 days

Month with highest number of rainy days is May (12.8 days).
Month with lowest number of rainy days is February (9.7 days).

  • Average snowfall in September: 0mm

Month with highest snowfall is January (312.4mm).
Months with lowest snowfall are May, June, July, August, September and October (0mm).

  • Average snowfall days in September: 0 days

Month with highest number of snowfall days is January (5.8 days).
Months with lowest number of snowfall days are May, June, July, August, September and October (0 days).

  • Average daylight in September: 12h

Months with longest days are May, June and July (Average daylight: 15h).
Month with shortest days is December (Average daylight: 9h).

  • Average sunshine in September: 7.5h

Month with most sunshine is July (Average sunshine: 9.5h).
Month with least sunshine is December (Average sunshine: 4.5h).

  • Average UV index in September: 6

Months with highest UV index are June, July and August (UV index 8).
Months with lowest UV index are January and December (UV index 1).