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
Observing a mild shift, the average high-temperature during September reduces from August's warm 77.5°F (25.3°C) to a refreshing 66°F (18.9°C). Troy logs a considerable temperature decrease from the daytime highs during the nights in September, with an average reading of 39.7°F (4.3°C).Humidity
The average relative humidity in September is 63%.Rainfall
In September, the rain falls for 8.5 days. Throughout September, 0.91" (23mm) of precipitation is accumulated. Throughout the year, there are 138.8 rainfall days, and 18.15" (461mm) of precipitation is accumulated.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.4 snowfall days, it receives 0.71" (18mm) of snow. In Troy, during the entire year, snow falls for 91.8 days and aggregates up to 49.33" (1253mm) of snow.Daylight
In Troy, the average length of the day in September is 12h and 34min.On the first day of September, sunrise is at 7:02 am and sunset at 8:24 pm. On the last day of the month, sunrise is at 7:42 am and sunset at 7:23 pm MDT.
Sunshine
In September, the average sunshine is 9h.UV index
The average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for average individuals.Note: The UV index of 3 in September translates into these instructions:
Undertake precautions - It is suggested to shield oneself from sunburn. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Be on the lookout! Nearly twofold UV radiation from the Sun can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September?
How many days does it rain in September?
When does it start to snow in Troy?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
How high is the UV index in September in Troy?
Average temperature in September
Troy, MT
- Average high temperature in September: 66°F
The warmest month (with the highest average high temperature) is August (77.5°F).
The month with the lowest average high temperature is December (27.1°F).
- Average low temperature in September: 39.7°F
The month with the highest average low temperature is August (47.3°F).
The coldest month (with the lowest average low temperature) is December (15.1°F).
Average pressure in September
Troy, MT
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.18"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Troy, MT
- Average wind speed in September: 3.9mph
The windiest months (with the highest average wind speed) are April and June (4.5mph).
The calmest month (with the lowest average wind speed) is December (3.5mph).
Average humidity in September
Troy, MT
- Average humidity in September: 63%
The month with the highest relative humidity is January (94%).
The month with the lowest relative humidity is August (53%).
Average rainfall in September
Troy, MT
- Average rainfall in September: 0.91"
The wettest month (with the highest rainfall) is December (2.24").
The driest month (with the least rainfall) is August (0.43").
Average rainfall days in September
Troy, MT
- Average rainfall days in September: 8.5 days
The month with the highest number of rainy days is April (17.5 days).
The month with the least rainy days is August (5.9 days).
Average snowfall in September
Troy, MT
- Average snowfall in September: 0.71"
The month with the highest snowfall is January (11.34").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Troy, MT
- Average snowfall days in September: 0.4 days
The month with the highest number of snowfall days is December (20 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Troy, MT
- Average daylight in September: 12h and 4min
The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 24min).
- Average sunshine in September: 9h and 0min
The months with the most sunshine are July and August (Average sunshine: 11h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 0min).
Average sunshine days in September
Troy, MT
- Average sunshine days in September: 19.5 days
The month with the most sunshine days is August (22.8 days).
The month with the least sunshine days is February (7.4 days).
Average UV index in September
Troy, MT
- Average UV index in September: 3
The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 1).
Average cloud cover in September
Troy, MT
- Average cloud cover in September: 26
The month with the most cloud cover is January (Cloud cover 70).
The month with the least cloud cover is August (Cloud cover 15).
Average visibility in September
Troy, MT
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August and September (6mi).
The month with the lowest visibility is January (2mi).
Troy, Montana, USA
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