United StatesAverage weather for Waltham in September
It's warm in September in Waltham with an average temperature of 24°C. Temperatures this month range from a low of 18°C to a high of 28°C. At night, you can expect temperatures between 11°C and 18°C.
Start of September
The month of September starts in Waltham with hot temps, averaging around 27°C during the day and nights around 17°C. You can expect regular precipitation, but there will also be some sunny days in the early part of the month.
With the temperature difference between day and night, it’s smart to wear layers.
Mid September
By mid-September, daytime temps drop to around 24°C, with nights around 15°C. There’s a chance of some showers during this time, but plenty of dry and sunny days too.
End of September
By the end of September, the average daytime temperature in Waltham is around 23°C, while nighttime temps are about 13°C. A shower might pop up, but overall, the weather will be dry and sunny.
In September, there is an average of 110 mm of precipitation, spread over 9 days. The wind speed is around 4 Bft, mostly coming from the South.
Waltham in September |
New York | ||
|---|---|---|---|
 Average temperature |
24°C | 27°C | |
 Max. temperature |
28°C | 31°C | |
| Min. temperature |
18°C | -5°C | |
 Total precipitation |
110 mm | 57 mm | |
| Rainy days |
9 days | 9 days | |
August
UV index
The UV index is a maximum of 5 this month. That's a moderate value on the intensity scale of 1 to 11. Unprotected skin can burn in about 30 minutes.
Is September a good time to visit Waltham?
Looking for sun? September isn’t a good month to be in Waltham. The temperature is nice, but there’s too much chance of rain.
Temperature records
With 36°C in 2018, Waltham reached the highest temperature in September over the past 10 years. The lowest daytime temperature in this month was 13°C in 2014. The extreme nighttime temperatures ranged from a lowest recorded value of 2°C to a highest value of 23°C.
Check out the climate of Waltham for all months and discover the best travel time
Daily Temperature in September in Waltham
This chart shows the average daily high and low temperatures in September for Waltham, in degrees Celsius. The red line represents the highs, and the blue line shows the lows. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, provide the average temperatures for this month.
Daily Precipitation in September in Waltham
The chart below shows the average daily precipitation in September for Waltham, measured in millimeters over the past few years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are listed at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that it rained more often. But remember, it’s just an average, and every day can be different. Based on historical weather data for September, you can expect about 9 days of precipitation in Waltham.
Daily UV index in September in Waltham
This chart shows the average daily UV index in September in Waltham, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Temperature in September in Waltham over the years
This chart shows the average temperature in September in Waltham, measured in degrees Celsius, over the past few years.
Total precipitation in September in Waltham over the years
This chart shows the average precipitation in September in Waltham, measured in millimeters over the past years. Precipitation is always measured as water, whether it’s snow or hail.
Daily weather in September for Waltham
Click on any day in September to get detailed info about the usual weather on that day in Waltham. Check out the historical temperatures and precipitation over the past 10 years on this day.
Weather experiences in September in Waltham
Have you been to Waltham in September?
Share your weather experience in September in Waltham.
Average weather in Waltham by month
Click on a month below to see detailed weather info for Waltham. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.
