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
The average high-temperature drops in September, from August's 85.3°F (29.6°C) to a still warm 75°F (23.9°C). A dramatic downturn marks the September nights in Lewiston, with lows averaging at a fresh 52.7°F (11.5°C).Humidity
The average relative humidity in September in Lewiston is 45%.Rainfall
In Lewiston, Idaho, in September, during 6.7 rainfall days, 0.39" (10mm) of precipitation is typically accumulated. In Lewiston, during the entire year, the rain falls for 142.4 days and collects up to 14.21" (361mm) of precipitation.Snowfall
In Lewiston, snow does not fall in May through September.Daylight
In September, the average length of the day in Lewiston is 12h and 32min.On the first day of the month, sunrise is at 6:09 am and sunset at 7:26 pm. On the last day of September, in Lewiston, sunrise is at 6:46 am and sunset at 6:29 pm PDT.
Sunshine
In Lewiston, Idaho, the average sunshine in September is 10.4h.UV index
The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The maximum UV index of 4 during September translates into these guidelines:
Undertake precautions - It is suggested to shield oneself from sunburn. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
Frequently asked questions
What are the temperatures in Lewiston in September?
What is the average humidity in September in Lewiston?
How many days does it rain in September in Lewiston?
When it does not snow in Lewiston?
Does it snow in Lewiston in September?
How many hours of daylight does Lewiston have in September?
What time are sunrise and sunset in September in Lewiston?
How long on average sun shines in September in Lewiston?
What is the UV index reading in September in Lewiston?
Average temperature in September
Lewiston, ID
- Average high temperature in September: 75°F
The warmest month (with the highest average high temperature) is August (85.3°F).
The month with the lowest average high temperature is December (36.1°F).
- Average low temperature in September: 52.7°F
The month with the highest average low temperature is August (59.2°F).
The coldest month (with the lowest average low temperature) is December (24.4°F).
Average pressure in September
Lewiston, ID
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.2"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).
Average wind speed in September
Lewiston, ID
- Average wind speed in September: 4.3mph
The windiest month (with the highest average wind speed) is April (5.7mph).
The calmest months (with the lowest average wind speed) are July, August and September (4.3mph).
Average humidity in September
Lewiston, ID
- Average humidity in September: 45%
The month with the highest relative humidity is January (84%).
The month with the lowest relative humidity is August (38%).
Average rainfall in September
Lewiston, ID
- Average rainfall in September: 0.39"
The wettest month (with the highest rainfall) is March (1.85").
The driest month (with the least rainfall) is August (0.31").
Average rainfall days in September
Lewiston, ID
- Average rainfall days in September: 6.7 days
The month with the highest number of rainy days is March (17.6 days).
The month with the least rainy days is August (5.2 days).
Average snowfall in September
Lewiston, ID
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.27").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Lewiston, ID
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is December (8.1 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Lewiston, ID
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in September: 10h and 2min
The month with the most sunshine is August (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 5h and 6min).
Average sunshine days in September
Lewiston, ID
- Average sunshine days in September: 21.9 days
The month with the most sunshine days is July (24 days).
The months with the least sunshine days are February and March (10.8 days).
Average UV index in September
Lewiston, ID
- Average UV index in September: 4
The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is February (UV index 1).
Average cloud cover in September
Lewiston, ID
- Average cloud cover in September: 18
The month with the most cloud cover is February (Cloud cover 48).
The months with the least cloud cover are July and August (Cloud cover 12).
Average visibility in September
Lewiston, ID
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February and December (5mi).
Lewiston, Idaho, USA
Weather forecast for your location
2. Allow the app to use your location
