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 onset of September coincides with a reduction in the average high-temperature, falling from a moderately hot 84.2°F (29°C) in August to a still warm 74.5°F (23.6°C). Herreid experiences a consistent average temperature of 54.5°F (12.5°C) throughout the nights in September.Humidity
In Herreid, the average relative humidity in September is 53%.Rainfall
In Herreid, in September, it is raining for 7.1 days, with typically 1.18" (30mm) of accumulated precipitation. Throughout the year, there are 89.4 rainfall days, and 15.39" (391mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
In Herreid, the average length of the day in September is 12h and 31min.On the first day of September, sunrise is at 7:02 am and sunset at 8:17 pm. On the last day of the month, sunrise is at 7:38 am and sunset at 7:21 pm CDT.
Sunshine
In September, the average sunshine in Herreid is 8.6h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for average individuals.Note: The UV index of 4 during September leads to these advisories:
Adopt protective measures - Suggestions to resist sunburn are offered. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. Tightly woven clothing, when worn loosely, shields effectively against the Sun.
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 in Herreid?
When it does not snow?
Does it snow in Herreid in September?
How many hours of daylight does Herreid have in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Herreid have in September?
What is the UV index intensity in September?
Average temperature in September
Herreid, SD
- Average high temperature in September: 74.5°F
The warmest month (with the highest average high temperature) is July (86.4°F).
The month with the lowest average high temperature is January (23°F).
- Average low temperature in September: 54.5°F
The month with the highest average low temperature is July (65.5°F).
The coldest month (with the lowest average low temperature) is January (9°F).
Average pressure in September
Herreid, SD
- Average pressure in September: 29.94"Hg
The months with the highest atmospheric pressure are January and February (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).
Average wind speed in September
Herreid, SD
- Average wind speed in September: 11.1mph
The windiest month (with the highest average wind speed) is April (11.5mph).
The calmest month (with the lowest average wind speed) is February (9.4mph).
Average humidity in September
Herreid, SD
- Average humidity in September: 53%
The month with the highest relative humidity is January (87%).
The month with the lowest relative humidity is August (52%).
Average rainfall in September
Herreid, SD
- Average rainfall in September: 1.18"
The wettest month (with the highest rainfall) is June (2.32").
The driest month (with the least rainfall) is January (0.47").
Average rainfall days in September
Herreid, SD
- Average rainfall days in September: 7.1 days
The month with the highest number of rainy days is June (13.8 days).
The month with the least rainy days is February (1.3 days).
Average snowfall in September
Herreid, SD
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.98").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Herreid, SD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Herreid, SD
- 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: 8h and 4min
The month with the most sunshine is July (Average sunshine: 11h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in September
Herreid, SD
- Average sunshine days in September: 19.6 days
The month with the most sunshine days is November (21.5 days).
The month with the least sunshine days is June (13.6 days).
Average UV index in September
Herreid, SD
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Herreid, SD
- Average cloud cover in September: 24
The month with the most cloud cover is January (Cloud cover 56).
The months with the least cloud cover are July and August (Cloud cover 21).
Average visibility in September
Herreid, SD
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
Herreid, South Dakota, USA
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