September weather forecastSaint John, IN
September
Weather in September
September, the first month of the autumn in Saint John, is also a moderately hot month, with an average temperature varying between 74.3°F (23.5°C) and 57.6°F (14.2°C).Temperature
Saint John's September weather features a light decline in high-temperatures, reducing from a warm 79.7°F (26.5°C) in August to a still moderately hot 74.3°F (23.5°C). In Saint John, the nighttime temperature averages to a mild 57.6°F (14.2°C) during September.Humidity
In Saint John, the average relative humidity in September is 77%.Rainfall
In Saint John, during September, the rain falls for 12.9 days and regularly aggregates up to 1.73" (44mm) of precipitation. Throughout the year, in Saint John, there are 143.5 rainfall days, and 21.02" (534mm) of precipitation is accumulated.Snowfall
In Saint John, snow does not fall in May through October.Daylight
In September, the average length of the day is 12h and 28min.On the first day of September, sunrise is at 6:16 am and sunset at 7:22 pm. On the last day of the month, sunrise is at 6:46 am and sunset at 6:32 pm CDT.
Sunshine
The average sunshine in September is 8.5h.UV index
The average daily maximum UV index in September in Saint John is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for the average person.Note: In September, the average maximum UV index of 4 translates into the following recommendations:
Undertake precautions - It is suggested to shield oneself from sunburn. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Saint John, IN
- Average high temperature in September: 74.3°F
The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (29.8°F).
- Average low temperature in September: 57.6°F
The month with the highest average low temperature is July (65.3°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in September
Saint John, IN
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Saint John, IN
- Average wind speed in September: 7.1mph
The windiest month (with the highest average wind speed) is January (10.2mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).
Average humidity in September
Saint John, IN
- Average humidity in September: 77%
The month with the highest relative humidity is February (83%).
The month with the lowest relative humidity is October (73%).
Average rainfall in September
Saint John, IN
- Average rainfall in September: 1.73"
The wettest month (with the highest rainfall) is May (2.83").
The driest months (with the least rainfall) are February and November (0.98").
Average rainfall days in September
Saint John, IN
- Average rainfall days in September: 12.9 days
The month with the highest number of rainy days is July (17.6 days).
The months with the least rainy days are January and February (5.3 days).
Average snowfall in September
Saint John, IN
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.87").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Saint John, IN
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Saint John, IN
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 8h and 30min
The months with the most sunshine are July and August (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in September
Saint John, IN
- Average sunshine days in September: 14.5 days
The month with the most sunshine days is November (17.9 days).
The month with the least sunshine days is July (10.5 days).
Average UV index in September
Saint John, IN
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Saint John, IN
- Average cloud cover in September: 33
The month with the most cloud cover is January (Cloud cover 62).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in September
Saint John, IN
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, August, September, October, November and December (6mi).
The months with the lowest visibility are January and July (5mi).
