Hartford
Connecticut, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Hartford, CT

Skyscape view of the city of Hartford, Connecticut, with the roads leading to the town, and trees on roadsides
Skyscape view of the city of Hartford, Connecticut, with the roads leading to the town, and trees on roadsides
September, the first month of the autumn, in Hartford, is also a moderately hot month, with average temperature varying between 73.4°F (23°C) and 55.2°F (12.9°C).

Temperature

In Hartford, the average high-temperature in September slightly decreases, from a moderately hot 81°F (27.2°C) in August, to a still warm 73.4°F (23°C). The average low-temperature, in Hartford, is 55.2°F (12.9°C).

Humidity

The average relative humidity in September is 77%.

Rainfall

September is the month with the least rainfall in Hartford. Rain falls for 8.2 days and accumulates 0.43" (11mm) of precipitation.

Snowfall

June through October are months without snowfall in Hartford.

Daylight

The average length of the day in September is 12.5h.

Sunshine

The average sunshine in September is 8.7h.

UV index

In Hartford, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from the exposure to the Sun's UV rays for average individuals.
Note: The average daily UV index of 4 in September transform into the following instructions:
Take precautions - Protection against the skin and eye damage is obliged. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.

What is the temperature in September in Hartford?

In Hartford, in September, the average high-temperature is 73.4°F (23°C), and the average low-temperature is 55.2°F (12.9°C).

What is the average humidity in September in Hartford?

In September, the average relative humidity in Hartford is 77%.

How many days does it rain in September in Hartford?

In Hartford, Connecticut, in September, during 8.2 rainfall days, 0.43" (11mm) of precipitation is typically accumulated.

What is the driest month in Hartford?

The month with the least rainfall in Hartford is September when the rain falls for 8.2 days and typically collects 0.43" (11mm) of precipitation.

When it does not snow in Hartford?

In Hartford, Connecticut, snow does not fall in June through October.

How many hours of daylight does Hartford have in September?

In September, the average length of the day is 12.5h.

How long on average sun shines in September in Hartford?

In Hartford, Connecticut, the average sunshine in September is 8.7h.

What is the UV index intensity in September in Hartford?

In September, the average daily maximum UV index in Hartford, Connecticut, is 4. A UV Index estimate of 3 to 5 represents a moderate health threat from unsafe exposure to the Sun's UV rays.
Average temperature in September - Hartford, CT
  • Average high temperature in September: 23°C

The warmest month (with the highest average high temperature) is July (28.3°C).
The month with the lowest average high temperature is January (0.6°C).

  • Average low temperature in September: 12.9°C

The month with the highest average low temperature is July (17.6°C).
The coldest month (with the lowest average low temperature) is January (-5.9°C).

Average humidity in September - Hartford, CT
  • Average humidity in September: 77%

The month with the highest relative humidity is February (79%).
The month with the lowest relative humidity is April (70%).

Average rainfall in September - Hartford, CT
  • Average rainfall in September: 11mm

Wettest months (with the highest rainfall) are June and July (27mm).
The driest month (with the lowest rainfall) is September (11mm).

Average rainfall days in September - Hartford, CT
  • Average rainfall days in September: 8.2 days

The month with the highest number of rainy days is July (11.8 days).
The month with the lowest number of rainy days is February (6.8 days).

Average snowfall in September - Hartford, CT
  • Average snowfall in September: 0mm

The month with the highest snowfall is February (29mm).
Months with the lowest snowfall are June, July, August, September and October (0mm).

Average snowfall days in September - Hartford, CT
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (5.7 days).
Months with the lowest number of snowfall days are June, July, August and September (0 days).

Average daylight in September / Average sunshine in September - Hartford, CT
  • Average daylight in September: 12.5h

The month with the longest days is June (Average daylight: 15.2h).
The month with shortest days is December (Average daylight: 9.2h).

  • Average sunshine in September: 8.7h

Months with most sunshine are July and August (Average sunshine: 10.4h).
The month with least sunshine is February (Average sunshine: 4.6h).

Average UV index in September - Hartford, CT
  • Average UV index in September: 4

Months with the highest UV index are June, July and August (UV index 6).
Months with the lowest UV index are January, February, March, November and December (UV index 2).