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September to kick off with drier air after August ties record for number of 90-degree days

An aerial view of a sandbar is highlighted by late afternoon sun near Essex Bay, Essex.David L. Ryan/Globe Staff

A cold front brought some showers this morning and this will put an end to the humidity which we’ve had the past few days. The air will become more refreshing, and some good sleeping weather is ahead.

Yesterday reached 91 degrees at Logan Airport. That marks the 11th time this month that we’ve had a 90-degree day, tying the record for the most number of 90-degree days in the month of August. This puts the total for the season at 21, which is a week above the 30-year average.

September Averages in Boston over the past 30 years.NOAA

The final numbers for climatological summer won’t be in until Thursday, but it looks like this summer will end up as at least the 4th warmest summer on record, but could rise to number two behind last year when the final numbers are in. Many of the warmest summers ever recorded have been since 2010. It’s just another data point in the fact summers in Southern New England are going to continue to become more and more uncomfortable as the climate heats up further.

The summer of 2021 was the warmest on record, but this year is also significantly above averageNOAA

September is going to start on an absolutely gorgeous note with plenty of sunshine and temperatures in the lower 80s. While this is above average for the time of year it certainly in the ballpark for what you’d expect. Humidity levels will be quite low and you’ll have to continue to water those containers as moisture loss will be high over the next few days.


A beautiful stretch of weather is on the way as we begin September this week.NOAA

While the days will be beautiful the nights are also going to be comfortable. Windows can be left open and sleeping weather should be at a premium. I expect temperatures Thursday morning to be in the upper 50s in the coolest spots and 60s elsewhere. It turns even cooler for Friday morning.

Dew points in the 50s Thursday will feel much more comfortable.WeatherBELL

The weekend brings back some humidity, especially for Sunday when temperatures could reach 90 degrees again. September averages at least one day of 90-degree weather, so this would not be out of the ordinary.


A cold front approaches Sunday night. This could bring a few more showers and thunderstorms. If the front keeps on moving, Monday will clear and we’ll see cooler and drier air. However, there is the chance that the front slows down or even stalls and this would leave us in cloudy, muggy conditions for Labor Day. I’d say there are equal chances for either possibility at this point so we’ll have to wait another couple of days to really nail down that part of the holiday weekend forecast.