Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
In Lewistown, the average high-temperature in September decreases from a moderately hot 78.1°F (25.6°C) in August to a comfortable 67.5°F (19.7°C). The temperature dips to an average of 47.1°F (8.4°C) during September nights.Humidity
The average relative humidity in September in Lewistown is 52%.Rainfall
In September, in Lewistown, the rain falls for 8.7 days. Throughout September, 1.02" (26mm) of precipitation is accumulated. Throughout the year, there are 126.2 rainfall days, and 17.83" (453mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through June, September through December. September is the first month it typically snows. Throughout September, in the average 1 snowfall days, it receives 1.3" (33mm) of snow. Throughout the year, there are 83.4 snowfall days, and 45.51" (1156mm) of snow is accumulated.Daylight
The average length of the day in September is 12h and 32min.On the first day of September, sunrise is at 6:38 am and sunset at 7:56 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 6:58 pm MDT.
Sunshine
In Lewistown, the average sunshine in September is 10h.UV index
In September, the average daily maximum UV index in Lewistown is 4. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for ordinary individuals.Note: The maximum UV index, 4 during September, leads to the following recommendations:
Put precautions into practice - Guidance to elude sunburn is provided. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat. Be mindful! The reflection from snow can increase the Sun's UV radiation nearly twice.
Frequently asked questions
What are the temperatures in Lewistown in September?
What is the average humidity in September in Lewistown?
How many days does it rain in September in Lewistown?
When does it start to snow in Lewistown?
What is the average length of the day in September in Lewistown?
What time are sunrise and sunset in September in Lewistown?
How many hours of sunshine does Lewistown have in September?
What is the UV index reading in September in Lewistown?
Average temperature in September
Lewistown, MT
- Average high temperature in September: 67.5°F
The warmest month (with the highest average high temperature) is July (78.8°F).
The months with the lowest average high temperature are February and December (29.1°F).
- Average low temperature in September: 47.1°F
The month with the highest average low temperature is August (54.5°F).
The coldest month (with the lowest average low temperature) is February (15.3°F).
Average pressure in September
Lewistown, MT
- Average pressure in September: 29.94"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Lewistown, MT
- Average wind speed in September: 8.5mph
The windiest months (with the highest average wind speed) are January, April and October (9.9mph).
The calmest month (with the lowest average wind speed) is August (7.4mph).
Average humidity in September
Lewistown, MT
- Average humidity in September: 52%
The month with the highest relative humidity is February (79%).
The month with the lowest relative humidity is August (47%).
Average rainfall in September
Lewistown, MT
- Average rainfall in September: 1.02"
The wettest month (with the highest rainfall) is May (3.39").
The driest month (with the least rainfall) is December (0.71").
Average rainfall days in September
Lewistown, MT
- Average rainfall days in September: 8.7 days
The month with the highest number of rainy days is May (19.3 days).
The month with the least rainy days is January (5.4 days).
Average snowfall in September
Lewistown, MT
- Average snowfall in September: 1.3"
The month with the highest snowfall is April (9.13").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Lewistown, MT
- Average snowfall days in September: 1 days
The month with the highest number of snowfall days is February (15.2 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Lewistown, MT
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 48min).
The month with the shortest days is December (Average daylight: 8h and 36min).
- Average sunshine in September: 10h and 0min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 30min).
Average sunshine days in September
Lewistown, MT
- Average sunshine days in September: 19.3 days
The month with the most sunshine days is September (19.3 days).
The month with the least sunshine days is April (8.3 days).
Average UV index in September
Lewistown, MT
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, March, April, October, November and December (UV index 2).
Average cloud cover in September
Lewistown, MT
- Average cloud cover in September: 23
The month with the most cloud cover is February (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 16).
Average visibility in September
Lewistown, MT
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Lewistown, Montana, USA
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