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
Grasmere observes a minor decrease in the average high-temperature with the arrival of September, falling from August's hot 89.4°F (31.9°C) to a moderately hot 79.2°F (26.2°C). The average temperature during September nights dips to a moderate 57.7°F (14.3°C).Humidity
In Grasmere, the average relative humidity in September is 32%.Rainfall
In September, the rain falls for 5.5 days. Throughout September, 0.24" (6mm) of precipitation is accumulated. Throughout the year, there are 100.2 rainfall days, and 7.48" (190mm) of precipitation is accumulated.Snowfall
In Grasmere, snow does not fall in May through September.Daylight
In September, the average length of the day is 12h and 28min.On the first day of September in Grasmere, Idaho, sunrise is at 7:09 am and sunset at 8:16 pm. On the last day of the month, sunrise is at 7:40 am and sunset at 7:26 pm MDT.
Sunshine
In September, the average sunshine is 9.7h.UV index
In Grasmere, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for ordinary individuals.Note: A maximum UV index of 5 in September translates into the following recommendations:
Undertake protective steps - Obligation to safeguard skin and eyes from harm is in place. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures in Grasmere?
What is the average humidity in September?
How many days does it rain in September in Grasmere?
When it does not snow?
Does it snow in September?
How many hours of daylight does Grasmere have in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Grasmere, ID
- Average high temperature in September: 79.2°F
The warmest month (with the highest average high temperature) is July (91.2°F).
The month with the lowest average high temperature is December (36.7°F).
- Average low temperature in September: 57.7°F
The month with the highest average low temperature is July (66.4°F).
The coldest month (with the lowest average low temperature) is December (26.1°F).
Average pressure in September
Grasmere, ID
- Average pressure in September: 29.93"Hg
The month with the highest atmospheric pressure is January (30.26"Hg).
The months with the lowest atmospheric pressure are June and August (29.88"Hg).
Average wind speed in September
Grasmere, ID
- Average wind speed in September: 6.5mph
The windiest month (with the highest average wind speed) is April (8.8mph).
The calmest months (with the lowest average wind speed) are January and September (6.5mph).
Average humidity in September
Grasmere, ID
- Average humidity in September: 32%
The month with the highest relative humidity is January (75%).
The month with the lowest relative humidity is July (25%).
Average rainfall in September
Grasmere, ID
- Average rainfall in September: 0.24"
The wettest month (with the highest rainfall) is December (1.06").
The driest month (with the least rainfall) is August (0.2").
Average rainfall days in September
Grasmere, ID
- Average rainfall days in September: 5.5 days
The month with the highest number of rainy days is March (14.3 days).
The months with the least rainy days are July and August (3.7 days).
Average snowfall in September
Grasmere, ID
- Average snowfall in September: 0"
The month with the highest snowfall is December (2.64").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Grasmere, ID
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is December (5.5 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
Grasmere, ID
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 9h and 4min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 12min).
Average sunshine days in September
Grasmere, ID
- Average sunshine days in September: 22.2 days
The month with the most sunshine days is July (24 days).
The month with the least sunshine days is March (13.6 days).
Average UV index in September
Grasmere, ID
- Average UV index in September: 5
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Grasmere, ID
- Average cloud cover in September: 13
The month with the most cloud cover is December (Cloud cover 35).
The months with the least cloud cover are July and August (Cloud cover 8).
Average visibility in September
Grasmere, ID
- 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).
Grasmere, Idaho, USA
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