Upper Alton Weather in May
Average highs run from 71°F on May 1 to 79°F on May 31, and lows from 51°F to 61°F. Normal precipitation for the month is 5.46 in over about 11 wet days.
May day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
May at a glance
- Average high
- 75°F
- Average low
- 56°F
- Precipitation
- 5.46 in
- Record high
- 98°FMay 16, 1944
- Record low
- 32°FMay 10, 1966
- Chance of a freeze
- 1%
- Daylight
- 13 h 50 min to 14 h 43 min
- Cloud cover
- 64%
- Humidity
- 78%
- Dew point
- 57°F
- Wind
- 9.4 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 |
|---|---|---|---|---|---|---|
| May 1 | 71°F | 51°F | 94°F 1953 | 34°F 1999 | 37% | 0% |
| May 2 | 72°F | 51°F | 94°F 1952 | 36°F 1966 | 37% | 0% |
| May 3 | 72°F | 52°F | 90°F 1949 | 34°F 1954 | 37% | 0% |
| May 4 | 72°F | 52°F | 96°F 1952 | 34°F 1957 | 37% | 0% |
| May 5 | 72°F | 52°F | 92°F 1952 | 37°F 1944 | 37% | 0% |
| May 6 | 73°F | 53°F | 93°F 1946 | 37°F 1944 | 37% | 0% |
| May 7 | 73°F | 53°F | 92°F 2007 | 38°F 1976 | 37% | 0% |
| May 8 | 73°F | 53°F | 88°F 1986 | 37°F 1947 | 37% | 0% |
| May 9 | 73°F | 54°F | 89°F 1986 | 35°F 1966 | 37% | 0% |
| May 10 | 73°F | 54°F | 87°F 1963 | 32°F 1966 | 37% | 0% |
| May 11 | 74°F | 54°F | 85°F 1944 | 40°F 1949 | 37% | 0% |
| May 12 | 74°F | 55°F | 89°F 1944 | 39°F 1960 | 37% | 0% |
| May 13 | 74°F | 55°F | 90°F 1956 | 39°F 1971 | 36% | 0% |
| May 14 | 74°F | 55°F | 92°F 1949 | 40°F 1953 | 36% | 0% |
| May 15 | 75°F | 56°F | 94°F 1944 | 43°F 1959 | 36% | 0% |
| May 16 | 75°F | 56°F | 98°F 1944 | 42°F 1983 | 36% | 0% |
| May 17 | 75°F | 57°F | 94°F 1944 | 42°F 1983 | 36% | 0% |
| May 18 | 75°F | 57°F | 91°F 1964 | 41°F 2002 | 36% | 0% |
| May 19 | 76°F | 57°F | 92°F 1944 | 41°F 2002 | 35% | 0% |
| May 20 | 76°F | 58°F | 92°F 1944 | 43°F 1954 | 35% | 0% |
| May 21 | 76°F | 58°F | 92°F 1962 | 43°F 2002 | 35% | 0% |
| May 22 | 77°F | 58°F | 93°F 1987 | 43°F 2002 | 35% | 0% |
| May 23 | 77°F | 59°F | 91°F 1950 | 43°F 1963 | 34% | 0% |
| May 24 | 77°F | 59°F | 96°F 1953 | 45°F 1956 | 34% | 0% |
| May 25 | 77°F | 59°F | 92°F 1953 | 44°F 1949 | 34% | 0% |
| May 26 | 78°F | 60°F | 98°F 1953 | 41°F 1961 | 34% | 0% |
| May 27 | 78°F | 60°F | 92°F 1977 | 44°F 1961 | 34% | 0% |
| May 28 | 78°F | 60°F | 91°F 1972 | 41°F 1947 | 33% | 0% |
| May 29 | 79°F | 61°F | 94°F 1953 | 40°F 1947 | 33% | 0% |
| May 30 | 79°F | 61°F | 92°F 2011 | 47°F 2021 | 33% | 0% |
| May 31 | 79°F | 61°F | 93°F 1946 | 42°F 1972 | 32% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (CDT).
- May 1
- sunrise 6:03 AM, sunset 7:53 PM
- May 31
- sunrise 5:37 AM, sunset 8:20 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00110137 (Alton - Melvin Price L&d), public domain. Records: NOAA GHCN-Daily, station USC00110137, 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.