Riverdale, NJ climate
Riverdale has chilly winters and warm summers, with plenty of rain. A typical July afternoon reaches 86°, a January night drops to 21°, and about 28 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decade6° warmer than normal today. The forecast high is 76°, and a typical Oct 1 in Riverdale peaks around 70°.Live forecast: National Weather Service · Normal: NOAA 1991–2020
What a year in Riverdale feels like
Winter
Spring
Summer
Fall
Riverdale 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 | 30-yr range |
|---|---|---|---|---|---|---|
| January | 38° | 21° | 3.4" | 9.6" | 11 | 21° – 36° |
| February | 41° | 22° | 2.7" | 7.7" | 9 | 19° – 38° |
| March | 49° | 29° | 3.9" | 5.3" | 11 | 33° – 49° |
| April | 62° | 39° | 3.9" | 1.4" | 10 | 46° – 55° |
| May | 72° | 49° | 4.0" | 0 | 11 | 56° – 66° |
| June | 81° | 58° | 4.6" | 0 | 11 | 67° – 72° |
| July | 86° | 64° | 4.4" | 0 | 9 | 70° – 79° |
| August | 84° | 62° | 4.5" | 0 | 9 | 69° – 76° |
| September | 77° | 55° | 4.5" | 0 | 8 | 63° – 70° |
| October | 65° | 43° | 4.5" | 0 | 8 | 50° – 60° |
| November | 53° | 34° | 3.6" | 0.2" | 8 | 39° – 48° |
| December | 43° | 26° | 4.2" | 3.9" | 11 | 28° – 45° |
| Year | 63° | 42° | 48.1" | 28.1" | 115 |
“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 Riverdale
Riverdale gets 48 inches of rain and melted snow a year. June is the wettest month and February the driest. Rain or snow falls on about 115 days a year.
About 188 frost-free days a year
In half of years the last 32° night comes by April 19 and the first one by October 23. That leaves about 188 frost-free days for gardens, longer than 62% of U.S. towns.
Heating and cooling a home in Riverdale
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Riverdale, 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.
Riverdale and its neighbors
Riverdale borders 5 towns with climate data. January nights across them vary by 1.2°. Kinnelon has the coldest January nights (19°) and Pequannock the hottest July afternoons (86°). Riverdale’s January low is 21° and its July high 86°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Riverdale 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 Riverdale averaged 2.1° warmer than the 1900s. The biggest change is in December (+3.5°). The shift is larger than in 96% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Riverdale’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 19° to 38°. June is the most reliable, staying within 6°.
Common questions about Riverdale’s climate
What is the coldest month in Riverdale?
January, with a typical high of 38° and a low of 21°.
What is the hottest month in Riverdale?
July, with a typical high of 86° and a low of 64°. About 14 days a year reach 90°.
How much snow does Riverdale get?
About 28 inches in a normal winter, most of it in January.
When is the first frost in Riverdale?
In half of years the first 32° night comes by October 23, and the last spring frost by April 19.
What is the rainiest month in Riverdale?
June, with 4.6 inches of rain and melted snow. The year totals 48 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Riverdale itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Oak Ridge Rsvr, NJ (10 mi, snow) and Wanaque Raymond Dam, NJ (4 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.