Johnston, RI climate
Johnston has chilly, snowy winters and pleasant summers, with plenty of rain. A typical July afternoon reaches 83°, a January night drops to 20°, and about 37 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Johnston feels like
Winter
Spring
Summer
Fall
Johnston weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 37° | 20° | 4.1" | 10.3" | 11 | 8 | 19° – 36° |
| February | 40° | 21° | 3.6" | 10.5" | 10 | 8 | 17° – 38° |
| March | 47° | 28° | 4.9" | 6.4" | 12 | 4 | 32° – 46° |
| April | 59° | 37° | 4.6" | 0.6" | 12 | 0 | 44° – 52° |
| May | 69° | 47° | 3.6" | 0 | 12 | 0 | 52° – 62° |
| June | 77° | 56° | 4.1" | 0 | 11 | 0 | 63° – 69° |
| July | 83° | 62° | 3.5" | 0 | 9 | 0 | 68° – 77° |
| August | 81° | 61° | 4.0" | 0 | 9 | 0 | 68° – 75° |
| September | 74° | 53° | 4.2" | 0 | 9 | 0 | 61° – 67° |
| October | 63° | 42° | 5.0" | 0.2" | 10 | 0 | 49° – 59° |
| November | 52° | 34° | 4.4" | 1.0" | 10 | 1 | 38° – 48° |
| December | 42° | 25° | 4.9" | 7.6" | 12 | 4 | 27° – 45° |
| Year | 60° | 41° | 50.6" | 36.6" | 127 | 25 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Johnston
Johnston gets 51 inches of rain and melted snow a year. October is the wettest month and July the driest. Rain or snow falls on about 127 days a year. Snow covers the ground about 25 days of the year.
About 199 frost-free days a year
In half of years the last 32° night comes by April 11 and the first one by October 30. That leaves about 199 frost-free days for gardens, longer than 72% of U.S. towns.
Heating and cooling a home in Johnston
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Johnston, 87% of that work is heating and 13% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Johnston and its neighbors
Johnston borders 5 towns with climate data. January nights across them vary by 3.2°. Scituate has the coldest January nights (19°) and Cranston the hottest July afternoons (83°). Johnston’s January low is 20° and its July high 83°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Johnston compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Johnston averaged 2.0° warmer than the 1900s. The biggest change is in December (+3.5°). The shift is larger than in 93% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Johnston’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. February swings the most: between 1991 and 2020 its average temperature ranged from 17° to 38°. June is the most reliable, staying within 6°.
Common questions about Johnston’s climate
What is the coldest month in Johnston?
January, with a typical high of 37° and a low of 20°.
What is the hottest month in Johnston?
July, with a typical high of 83° and a low of 62°. About 12 days a year reach 90°.
How much snow does Johnston get?
About 37 inches in a normal winter, most of it in February.
When is the first frost in Johnston?
In half of years the first 32° night comes by October 30, and the last spring frost by April 11.
What is the rainiest month in Johnston?
October, with 5.0 inches of rain and melted snow. The year totals 51 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Johnston itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Providence T F Green Airport, RI (9 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.