Climate averages 1991–2020

Troy weather
in December.

A cold month with moderate precipitation: the 10th warmest and the 2nd driest of the year.

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

Average high 1.9°C Daytime mean, December
Average low -3.9°C Night-time mean, December
Precipitation 57 mm 9 days with ≥1 mm
Daylight 9 h Sunrise to sunset, per day
Every month in Troy · average highYear overview

December is a cold month in Troy: daytime highs average 1.9°C and nights cool to about -3.9°C. By daytime temperature it is the 10th warmest of the 12 months.

Expect about 57 mm of precipitation on roughly 9 days, which makes December a month with moderate precipitation (the 2nd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 9 h 07 min on an average December day.

The nearest other city in this atlas is Rochester Hills (6 km away). In December its highs average 1.8°C, about as warm as Troy, with 56 mm of precipitation.

Among the 498 cities listed in the United States, Troy ranks joint 453rd of 498 for the warmest December highs and joint 191st of 498 for the driest December (precipitation, lowest first). The mean December high of those 498 cities is 10.5°C; Troy is 8.7°C cooler than that mean.

From December to January, average highs fall by 2.7°C to -0.9°C, and monthly precipitation rises from 57 mm to 60 mm.

The annual picture

December 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. -15-10-5051015202530 JanFebMarAprMayJunJulAugSepOctNovDec

Monthly precipitation

Average total · mm
Average monthly precipitation totalsEach bar is a mean monthly total over 1991–2020. Full numbers are in the table. JanFebMarAprMayJunJulAugSepOctNovDec 1000

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

Every month, side by side

Troy climate table

1991–2020
Monthly climate averages for Troy, 1991–2020
MonthAverage highHigh / lowAverage lowPrecipitation mm/monthWet days ≥1 mm/dayDaylight hours/dayDay­light h/day
January -0.9°C-8.1°C-8.1°C609.69.49 h
February 0.6°C-7.7°C-7.7°C528.010.511 h
March 6.0°C-3.1°C-3.1°C619.711.912 h
April 13.0°C3.4°C3.4°C9012.013.313 h
May 19.6°C10.1°C10.1°C9412.714.615 h
June 24.8°C15.9°C15.9°C9411.215.315 h
July 27.0°C18.5°C18.5°C8011.415.015 h
August 25.9°C17.9°C17.9°C8010.213.914 h
September 22.1°C14.2°C14.2°C709.012.513 h
October 15.1°C7.9°C7.9°C719.611.111 h
November 7.8°C1.5°C1.5°C669.39.810 h
December, selected 1.9°C-3.9°C-3.9°C579.29.19 h

Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet 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

December in nearby cities

Distance from Troy

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 Troy) is explained once on the Troy year overview and on the Sources, method and limits page.

Southfield lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.