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
September ushers in a minute temperature change, with average high-temperatures reducing from August's tropical 89.4°F (31.9°C) to a warm 83.7°F (28.7°C). The nighttime temperature dips to a refreshing 63.5°F (17.5°C) on average during September.Heat index
For most parts of September, the heat index is calculated to be a hot 89.6°F (32°C). Long-standing exposure and activity could induce a feeling of tiredness and lead to heat cramps.Records show heat index calculations are tailored for shaded regions and mild winds. Heat index values may surge by up to 15 Fahrenheit (8 Celsius) degrees in the presence of direct sunlight.
Note: The heat index, also known as 'feels like' or 'apparent temperature', reflects the blend of air temperature and relative humidity to give a temperature impression. Additional elements including metabolic differences, the level of physical activity, and attire have a role in shaping the individual's temperature perception. In the direct sunlight, the weather's impact can be amplified, possibly boosting the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values remain especially vital for babies and toddlers. Children frequently underestimate the importance of resting and drinking fluids. Thirst is a symptom of advanced dehydration - hence the need to hydrate regularly, especially during protracted physical exercises.
Humidity
The average relative humidity in September is 72%.Rainfall
September is the month with the least rainfall. Rain falls for 9.7 days and accumulates 0.79" (20mm) of precipitation.Snowfall
In San Mateo, snow does not fall in April through November.Daylight
In San Mateo, the average length of the day in September is 12h and 23min.On the first day of September, sunrise is at 7:04 am and sunset at 7:56 pm. On the last day of the month, sunrise is at 7:25 am and sunset at 7:15 pm EDT.
Sunshine
In San Mateo, the average sunshine in September is 8.5h.UV index
The average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for average individuals.Note: In September, a daily maximum UV index of 5 leads to the following instructions:
Exercise prevention - Warding off sunburn is urged. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is it in September?
What is the average humidity in September?
What is the driest month?
How many days does it rain in September?
When it does not snow?
What is the average length of the day in September?
When are sunrise and sunset in September in San Mateo?
How many hours of sunshine does San Mateo have in September?
How high is the UV index in September in San Mateo?
Average temperature in September
San Mateo, SC
- Average high temperature in September: 83.7°F
The warmest month (with the highest average high temperature) is July (91°F).
The month with the lowest average high temperature is January (50.2°F).
- Average low temperature in September: 63.5°F
The month with the highest average low temperature is July (69.4°F).
The coldest month (with the lowest average low temperature) is January (34.5°F).
Average pressure in September
San Mateo, SC
- Average pressure in September: 30.03"Hg
The months with the highest atmospheric pressure are January and November (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.99"Hg).
Average wind speed in September
San Mateo, SC
- Average wind speed in September: 5.2mph
The windiest month (with the highest average wind speed) is February (7mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).
Average humidity in September
San Mateo, SC
- Average humidity in September: 72%
The month with the highest relative humidity is December (77%).
The month with the lowest relative humidity is July (69%).
Average rainfall in September
San Mateo, SC
- Average rainfall in September: 0.79"
The wettest month (with the highest rainfall) is August (2.28").
The driest month (with the least rainfall) is September (0.79").
Average rainfall days in September
San Mateo, SC
- Average rainfall days in September: 9.7 days
The month with the highest number of rainy days is July (15.4 days).
The month with the least rainy days is October (7.2 days).
Average snowfall in September
San Mateo, SC
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.31").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").
Average snowfall days in September
San Mateo, SC
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (0.9 days).
The months with the least snowfall days are April, May, June, July, August, September, October and November (0 days).
Average daylight in September /
Average sunshine in September
San Mateo, SC
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in September: 8h and 3min
The month with the most sunshine is July (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 6min).
Average sunshine days in September
San Mateo, SC
- Average sunshine days in September: 18.5 days
The month with the most sunshine days is October (22.6 days).
The month with the least sunshine days is July (14.3 days).
Average UV index in September
San Mateo, SC
- Average UV index in September: 5
The month with the highest UV index is June (UV index 7).
The months with the lowest UV index are January and December (UV index 2).
Average cloud cover in September
San Mateo, SC
- Average cloud cover in September: 32
The month with the most cloud cover is February (Cloud cover 45).
The months with the least cloud cover are June and July (Cloud cover 29).
Average visibility in September
San Mateo, SC
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
San Mateo, South Carolina, USA
Weather forecast for your location
2. Allow the app to use your location