Climate averages 1991–2020

Quincy weather
in September.

A mild, moderately wet month: the 4th warmest and the 6th driest of the year.

Long-term climate patterns, not a forecast for a particular trip.

Average high 21.9°C Daytime mean, September
Average low 14.8°C Night-time mean, September
Rainfall 88 mm 8 days with ≥1 mm
Daylight 13 h Sunrise to sunset, per day
Every month in Quincy · average highYear overview

September is a mild month in Quincy: daytime highs average 21.9°C and nights cool to about 14.8°C. By daytime temperature it is the 4th warmest of the 12 months.

Expect about 88 mm of rain on roughly 8 days, which makes September a moderately wet month (the 6th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 32 min on an average September day.

The nearest other city in this atlas is Dorchester (8 km away). In September its highs average 22.2°C, about as warm as Quincy, with 88 mm of rain.

Among the 498 cities listed in the United States, Quincy ranks joint 463rd of 498 for the warmest September highs and joint 324th of 498 for the driest September (rainfall, lowest first). The mean September high of those 498 cities is 26.9°C; Quincy is 5.0°C cooler than that mean.

From September to October, average highs fall by 6.0°C to 15.9°C, and monthly rainfall rises from 88 mm to 108 mm.

The annual picture

September in context

30-year average
Average highAverage low°C
Average daily high and low temperatures by month The same values are available in the monthly table below. Lines show mean daily maxima and minima, not a forecast interval. -10-5051015202530 JanFebMarAprMayJunJulAugSepOctNovDec

Monthly rainfall

Average total · mm
Average monthly rainfall totalsEach bar is a mean monthly total over 1991–2020. Full numbers are in the table. JanFebMarAprMayJunJulAugSepOctNovDec 1500

Averages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated

Every month, side by side

Quincy climate table

1991–2020
Monthly climate averages for Quincy, 1991–2020
MonthAverage highHigh / lowAverage lowRainfall mm/monthRain days ≥1 mm/dayDaylight hours/dayDay­light h/day
January 2.0°C-5.4°C-5.4°C9410.09.59 h
February 3.2°C-4.6°C-4.6°C848.910.511 h
March 6.6°C-1.2°C-1.2°C11611.111.912 h
April 12.5°C4.2°C4.2°C10011.013.313 h
May 18.0°C9.7°C9.7°C8110.614.615 h
June 23.2°C15.2°C15.2°C8710.115.215 h
July 26.6°C18.8°C18.8°C739.614.915 h
August 25.8°C18.3°C18.3°C859.113.914 h
September, selected 21.9°C14.8°C14.8°C888.112.513 h
October 15.9°C9.0°C9.0°C1089.811.111 h
November 10.0°C3.4°C3.4°C959.69.810 h
December 4.9°C-1.6°C-1.6°C11510.89.29 h

Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.

Compare places

September in nearby cities

Distance from Quincy

Read the numbers correctly

Climate, not a promise.

These patterns help compare months. They cannot tell you the weather on a specific day of your trip.

Sources, method and limits

How these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Quincy) is explained once on the Quincy year overview and on the Sources, method and limits page.

Boston and Dorchester lie in the same rainfall cell, so their rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.