September weather forecastHempstead, NY
September
Weather in September
September marks the onset of fall in Hempstead, New York, with the weather significantly cooling down from the summer temperatures of August. The month is characterized by a substantial decrease in temperature, signaling the transition from summer to fall. In contrast to August, September witnesses a notable dip in rainfall, with precipitation levels falling to 0.31" (8mm). The wind speed picks up this change becoming slightly gustier, but remains relatively unthreatening at an average of 9.4mph (15.1km/h). Despite the reduction in daylight hours from August, the city still enjoys long daylight hours, serving as an indicator of prolonged outdoor activities.Temperature
Hempstead's weather subtly changes with the onset of September, barely falling from a warm 79.2°F (26.2°C) in August to an agreeable 72.5°F (22.5°C). Hempstead registers an average low-temperature of 64.6°F (18.1°C) throughout September, a modest decrease from its daytime highs.Humidity
In September, the average relative humidity in Hempstead is 74%.Rainfall
The month with the least rainfall in Hempstead, New York, is September, when the rain falls for 8.7 days and typically collects 0.31" (8mm) of precipitation.Snowfall
In Hempstead, snow does not fall in April through November.Daylight
In Hempstead, the average length of the day in September is 12h and 27min.On the first day of September, sunrise is at 6:22 am and sunset at 7:26 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 6:37 pm EDT.
Sunshine
In Hempstead, the average sunshine in September is 9.1h.UV index
The average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for the ordinary person.Note: A typical high UV index of 5 in September suggests the following recommendations:
Preventative actions are necessary - The mandate to avoid skin and eye damage is in place. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Hempstead, NY
- Average high temperature in September: 72.5°F
The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (37.6°F).
- Average low temperature in September: 64.6°F
The month with the highest average low temperature is July (71.4°F).
The coldest month (with the lowest average low temperature) is January (28.8°F).
Average pressure in September
Hempstead, NY
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Hempstead, NY
- Average wind speed in September: 9.4mph
The windiest month (with the highest average wind speed) is January (12.7mph).
The calmest month (with the lowest average wind speed) is July (8.3mph).
Average humidity in September
Hempstead, NY
- Average humidity in September: 74%
The month with the highest relative humidity is May (77%).
The month with the lowest relative humidity is November (71%).
Average rainfall in September
Hempstead, NY
- Average rainfall in September: 0.31"
The wettest month (with the highest rainfall) is July (0.98").
The driest month (with the least rainfall) is September (0.31").
Average rainfall days in September
Hempstead, NY
- Average rainfall days in September: 8.7 days
The month with the highest number of rainy days is July (12.7 days).
The months with the least rainy days are January and November (5.2 days).
Average snowfall in September
Hempstead, NY
- Average snowfall in September: 0"
The month with the highest snowfall is March (0.2").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").
Average snowfall days in September
Hempstead, NY
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (3.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Hempstead, NY
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 9h and 6min
The month with the most sunshine is July (Average sunshine: 10h and 54min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days in September
Hempstead, NY
- Average sunshine days in September: 19 days
The month with the most sunshine days is January (23.4 days).
The month with the least sunshine days is June (14.9 days).
Average UV index in September
Hempstead, NY
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March and December (UV index 2).
Average cloud cover in September
Hempstead, NY
- Average cloud cover in September: 32
The months with the most cloud cover are February and December (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 27).
Average visibility in September
Hempstead, NY
- 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).
