Rio Weather in December
Average highs run from 37°F on December 1 to 28°F on December 31, and lows from 21°F to 11°F. Normal precipitation for the month is 1.45 in over about 8 wet days.
December day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
December at a glance
- Average high
- 32°F
- Average low
- 16°F
- Precipitation
- 1.45 in
- Snowfall
- 10.7 in
- Record high
- 68°FDec 15, 2021
- Record low
- -25°FDec 19, 1983
- Chance of a freeze
- 100%
- Daylight
- 9 h 12 min to 9 h 01 min
- Cloud cover
- 67%
- Humidity
- 89%
- Dew point
- 20°F
- Wind
- 11.2 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| Dec 1 | 37°F | 21°F | 62°F 1970 | -1°F 1971 | 26% | 12% |
| Dec 2 | 37°F | 20°F | 62°F 1982 | -10°F 1940 | 26% | 12% |
| Dec 3 | 36°F | 20°F | 65°F 2012 | -16°F 1940 | 26% | 13% |
| Dec 4 | 36°F | 20°F | 61°F 2017 | -6°F 1977 | 26% | 13% |
| Dec 5 | 35°F | 19°F | 64°F 2001 | -3°F 2007 | 26% | 13% |
| Dec 6 | 35°F | 19°F | 56°F 1998 | -11°F 1972 | 26% | 14% |
| Dec 7 | 35°F | 19°F | 60°F 1946 | -15°F 1972 | 26% | 14% |
| Dec 8 | 34°F | 18°F | 63°F 1946 | -7°F 1958 | 26% | 14% |
| Dec 9 | 34°F | 18°F | 60°F 1946 | -11°F 1958 | 25% | 14% |
| Dec 10 | 34°F | 18°F | 56°F 2015 | -14°F 1958 | 25% | 15% |
| Dec 11 | 33°F | 17°F | 59°F 1949 | -17°F 1972 | 25% | 15% |
| Dec 12 | 33°F | 17°F | 53°F 1965 | -10°F 1962 | 25% | 15% |
| Dec 13 | 33°F | 17°F | 60°F 2015 | -13°F 1976 | 25% | 15% |
| Dec 14 | 32°F | 16°F | 59°F 1975 | -12°F 1972 | 25% | 15% |
| Dec 15 | 32°F | 16°F | 68°F 2021 | -15°F 1961 | 25% | 15% |
| Dec 16 | 32°F | 16°F | 63°F 2021 | -12°F 1972 | 25% | 15% |
| Dec 17 | 31°F | 15°F | 52°F 1939 | -13°F 1972 | 25% | 16% |
| Dec 18 | 31°F | 15°F | 53°F 2002 | -18°F 1983 | 24% | 16% |
| Dec 19 | 31°F | 15°F | 51°F 1988 | -25°F 1983 | 24% | 16% |
| Dec 20 | 31°F | 14°F | 53°F 1967 | -17°F 1963 | 24% | 16% |
| Dec 21 | 30°F | 14°F | 54°F 1967 | -18°F 1989 | 24% | 16% |
| Dec 22 | 30°F | 14°F | 53°F 2019 | -17°F 1983 | 24% | 16% |
| Dec 23 | 30°F | 14°F | 55°F 1941 | -21°F 1983 | 24% | 16% |
| Dec 24 | 30°F | 13°F | 52°F 1955 | -23°F 1983 | 24% | 16% |
| Dec 25 | 29°F | 13°F | 56°F 1982 | -21°F 2000 | 24% | 16% |
| Dec 26 | 29°F | 13°F | 51°F 2023 | -22°F 1962 | 24% | 17% |
| Dec 27 | 29°F | 12°F | 55°F 1946 | -21°F 1950 | 24% | 17% |
| Dec 28 | 29°F | 12°F | 62°F 1984 | -15°F 2000 | 24% | 17% |
| Dec 29 | 28°F | 12°F | 55°F 2022 | -12°F 1976 | 24% | 17% |
| Dec 30 | 28°F | 12°F | 56°F 2004 | -14°F 2013 | 24% | 17% |
| Dec 31 | 28°F | 11°F | 55°F 1965 | -16°F 1967 | 23% | 17% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (CST).
- December 1
- sunrise 7:10 AM, sunset 4:22 PM
- December 31
- sunrise 7:30 AM, sunset 4:31 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00470308 (Arlington), public domain. Records: NOAA GHCN-Daily, station USW00014837, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.