Union climate

Union Weather in May

NOAA 1991-2020 normals for Marengo, 6.4 km from Union

Average highs run from 65°F on May 1 to 75°F on May 31, and lows from 42°F to 52°F. Normal precipitation for the month is 4.57 in over about 12 wet days.

May day by day

The normal high and low for each date, and the record, in °F.

Normal daily high and low temperature at Union, in °F, with the record for each date.20406080100151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

May at a glance

Average high
70°F
Average low
47°F
Precipitation
4.57 in
Record high
96°FMay 28, 2012
Record low
24°FMay 7, 1989
Chance of a freeze
42%
Days of 90°F or more
0.9
Daylight
14 h 04 min to 15 h 02 min
Cloud cover
66%
Humidity
77%
Dew point
51°F
Wind
10.7 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.

DateNormal highNormal lowRecord highRecord lowChance wetChance of snow
May 165°F42°F85°F 201328°F 197838%
May 265°F43°F90°F 199229°F 196638%
May 366°F43°F84°F 202127°F 200538%
May 466°F43°F86°F 198029°F 200538%
May 566°F44°F87°F 198030°F 198738%
May 667°F44°F85°F 200028°F 198938%
May 767°F44°F86°F 200424°F 198938%
May 868°F45°F87°F 202331°F 198938%
May 968°F45°F88°F 201427°F 196638%
May 1068°F45°F87°F 199325°F 196638%
May 1169°F46°F91°F 201128°F 198938%0%
May 1269°F46°F92°F 201130°F 198138%0%
May 1369°F46°F92°F 202232°F 202138%0%
May 1470°F47°F91°F 202235°F 198838%0%
May 1570°F47°F93°F 201334°F 201638%0%
May 1670°F47°F93°F 202532°F 201437%0%
May 1771°F48°F88°F 197733°F 201437%0%
May 1871°F48°F90°F 198733°F 200237%0%
May 1971°F48°F94°F 197534°F 200237%0%
May 2072°F49°F94°F 197535°F 198137%0%
May 2172°F49°F90°F 201231°F 200237%0%
May 2272°F49°F91°F 197534°F 200637%0%
May 2373°F49°F91°F 197535°F 196937%0%
May 2473°F50°F91°F 201036°F 199236%0%
May 2573°F50°F92°F 201030°F 198836%0%
May 2674°F50°F95°F 198536°F 197936%0%
May 2774°F51°F93°F 198530°F 199236%0%
May 2874°F51°F96°F 201233°F 199236%0%
May 2975°F51°F93°F 200635°F 198436%0%
May 3075°F52°F93°F 200635°F 202135%0%
May 3175°F52°F91°F 199441°F 201535%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Union, in percent, and of at least 0.1 inch of snowfall.0102030401102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (CDT).

May 1
sunrise 5:50 AM, sunset 7:54 PM
May 31
sunrise 5:21 AM, sunset 8:23 PM

Every day of May: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00115326 (Marengo), public domain. Records: NOAA GHCN-Daily, station USC00112223, 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.