- Save up to 50% on group tours in the Tucan Travel sale
- Book adventures to the Americas, Africa, Europe & more
- Discount varies by tour. 5% Loyalty Discount also available
Keystone weather in September 2019
- 23°C max day temperature
23
- 9 hours of sunshine per day
9
- 8 days with some rainfall
8
- 6°C min night temperature
6
- 12 hours of daylight per day
12
- No heat & humidity
0
- 32 mm of monthly rainfall
32
- 6 (High) UV index
6
Going to Keystone? Find the best month to visit Keystone based on the weather.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Expect 23°C daytime maximum temperatures in the shade with on average 9 hours of sunshine per day in Keystone in September. Check more long-term weather averages for Keystone in September before you book your next holiday to South Dakota in 2019/2020.
Expires at 23:59 on Wednesday 6th Mar 2019 · View all Tucan Travel offers
More about Keystone
- Weather overview
- Climate guide
- 5-day forecast
- Best time to go
- Weather by month
- Today's conditions
- Compare weather
- Sunrise & Sunset
- USA snow reports
- More destinations
- Top deals & discounts
- Back to South Dakota
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
The September weather guide for Keystone, South Dakota shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.
Metric (°C / mm) | Imperial (°F / inches)
Guide to Keystone weather in September
The average maximum daytime temperature in Keystone in September is a warm 23°C (73°F). The average night-time temperature is usually a cold 6°C (43°F). There are usually 9 hours of bright sunshine each day, which represents 68% of the 12 hours of daylight.
Expect 32mm (1.3 inches) of rainfall across the whole of September with 8 days with some rain falling. Maximum UV levels will be high (6 UV index) at midday when the skies are clear.
Keystone sunrise & sunset times for September 2019
Browse the sunrise & sunset times for Keystone in September 2019. Select a month to view Keystone sunrise & sunset times for the next twelve months.
JanFebMarAprMayJunJulAugSepOctNovDec
Date | Sunrise times | Sunset times |
---|---|---|
Sunday, 1st September 2019 | 06:17 | 19:30 |
Monday, 2nd September 2019 | 06:18 | 19:28 |
Tuesday, 3rd September 2019 | 06:19 | 19:26 |
Wednesday, 4th September 2019 | 06:20 | 19:24 |
Thursday, 5th September 2019 | 06:21 | 19:23 |
Friday, 6th September 2019 | 06:22 | 19:21 |
Saturday, 7th September 2019 | 06:24 | 19:19 |
Sunday, 8th September 2019 | 06:25 | 19:17 |
Monday, 9th September 2019 | 06:26 | 19:15 |
Tuesday, 10th September 2019 | 06:27 | 19:13 |
Wednesday, 11th September 2019 | 06:28 | 19:12 |
Thursday, 12th September 2019 | 06:29 | 19:10 |
Friday, 13th September 2019 | 06:30 | 19:08 |
Saturday, 14th September 2019 | 06:32 | 19:06 |
Sunday, 15th September 2019 | 06:33 | 19:04 |
Monday, 16th September 2019 | 06:34 | 19:02 |
Tuesday, 17th September 2019 | 06:35 | 19:01 |
Wednesday, 18th September 2019 | 06:36 | 18:59 |
Thursday, 19th September 2019 | 06:37 | 18:57 |
Friday, 20th September 2019 | 06:38 | 18:55 |
Saturday, 21st September 2019 | 06:40 | 18:53 |
Sunday, 22nd September 2019 | 06:41 | 18:51 |
Monday, 23rd September 2019 | 06:42 | 18:50 |
Tuesday, 24th September 2019 | 06:43 | 18:48 |
Wednesday, 25th September 2019 | 06:44 | 18:46 |
Thursday, 26th September 2019 | 06:45 | 18:44 |
Friday, 27th September 2019 | 06:46 | 18:42 |
Saturday, 28th September 2019 | 06:48 | 18:40 |
Sunday, 29th September 2019 | 06:49 | 18:38 |
Monday, 30th September 2019 | 06:50 | 18:37 |
- Save an extra 10% on cheap car hire worldwide
- With this exclusive Holiday Autos discount code
- Travel before 31st December 2019 (inclusive)
Expires at 23:59 on Thursday 28th Feb 2019 · View all Holiday Autos offers
More South Dakota destinations
All South Dakota destinations >>
All destinations (A to Z)
Can't see your chosen destination? Use our A to Z search to find your required the holiday weather guide:
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Get FREE travel offers
Sign up to receive the latest deals and exclusive discounts on holidays, flights, hotels and more, plus inspiration on where to go when
We promise not to share your details