September weather forecastNewcastle, WY
September
Weather in September
The arrival of September signals the transition from summer to autumn in Newcastle. While noticeably cooler compared to August, September remains pleasant and offers many sunbathing opportunities. September marks the return of the snowfall, albeit a scanty 0.59" (15mm). The milder temperature welcomes the start of the harvest season, showcasing the rich produce of the land. One would encounter a dramatic play of colours as leaves begin their fall metamorphosis.Temperature
Transitioning from August to September in Newcastle involves a subtle drop in average high-temperatures, descending from a warm 77.2°F (25.1°C) to a pleasant 68.5°F (20.3°C). During September, Newcastle's temperature falls to a steady low-temperature average of 48.2°F (9°C).Humidity
The average relative humidity in September is 54%.Rainfall
In Newcastle, in September, it is raining for 10 days, with typically 1.26" (32mm) of accumulated precipitation. Throughout the year, there are 123.2 rainfall days, and 19.37" (492mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through June, September through December. September is the first month it typically snows. Throughout September, in the average 0.8 snowfall days, it receives 0.59" (15mm) of snow. In Newcastle, during the entire year, snow falls for 80.3 days and aggregates up to 41.38" (1051mm) of snow.Daylight
The average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 6:21 am and sunset at 7:31 pm. On the last day of September, sunrise is at 6:54 am and sunset at 6:38 pm MDT.
Sunshine
The average sunshine in September is 10.6h.UV index
In Newcastle, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for ordinary individuals.Note: The maximum daily UV index of 4 in September interprets into the following recommendations:
Be vigilant - Preventing sunburn is recommended. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear. Mind this! Nearly twice the UV radiation from the Sun can be reflected by the snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Newcastle, WY
- Average high temperature in September: 68.5°F
The warmest month (with the highest average high temperature) is July (79.2°F).
The month with the lowest average high temperature is December (26.2°F).
- Average low temperature in September: 48.2°F
The month with the highest average low temperature is July (57.7°F).
The coldest month (with the lowest average low temperature) is February (10.8°F).
Average pressure in September
Newcastle, WY
- Average pressure in September: 29.93"Hg
The months with the highest atmospheric pressure are January and December (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).
Average wind speed in September
Newcastle, WY
- Average wind speed in September: 8.7mph
The windiest month (with the highest average wind speed) is April (10.3mph).
The calmest month (with the lowest average wind speed) is August (7.8mph).
Average humidity in September
Newcastle, WY
- Average humidity in September: 54%
The month with the highest relative humidity is February (84%).
The month with the lowest relative humidity is August (53%).
Average rainfall in September
Newcastle, WY
- Average rainfall in September: 1.26"
The wettest months (with the highest rainfall) are June and July (2.68").
The driest month (with the least rainfall) is December (0.67").
Average rainfall days in September
Newcastle, WY
- Average rainfall days in September: 10 days
The month with the highest number of rainy days is June (17.9 days).
The month with the least rainy days is February (3.7 days).
Average snowfall in September
Newcastle, WY
- Average snowfall in September: 0.59"
The month with the highest snowfall is April (8.82").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Newcastle, WY
- Average snowfall days in September: 0.8 days
The month with the highest number of snowfall days is January (12.8 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Newcastle, WY
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in September: 10h and 36min
The month with the most sunshine is August (Average sunshine: 11h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 36min).
Average sunshine days in September
Newcastle, WY
- Average sunshine days in September: 15.4 days
The month with the most sunshine days is November (18.7 days).
The month with the least sunshine days is June (9.7 days).
Average UV index in September
Newcastle, WY
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, March, April, October, November and December (UV index 2).
Average cloud cover in September
Newcastle, WY
- Average cloud cover in September: 18
The month with the most cloud cover is February (Cloud cover 43).
The month with the least cloud cover is August (Cloud cover 17).
Average visibility in September
Newcastle, WY
- 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).
