Waukegan, IL Climate: Temperature by Month
Pulled from NOAA NCEI 1991–2020 normals →: climate measurements used in PlainClimate's documented score
30-year climate normals (1991-2020) from Waukegan's primary NOAA station, WAUKEGAN.
The climate verdict for Waukegan
Waukegan, Illinois has a mixed annual climate rather than one dominant extreme. Its NOAA normal shows an annual average of 48°F. July is the warmest month at 72°F and January the coldest at 23°F.
- 48°F
- yearly average temperature, NOAA normal
- 172 days
- frost-free days per growing season
Waukegan: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00119029 · Waukegan, IL 48°F mean
TEMP-COOL · RANK-COOL · PHOTO-FINISH · PRCP-UNK · SWING-WIDE · COMF-UNK · LOAD-HEAT · STN-1 · BOOK-PART
- TEMP-COOL 48°F
- RANK-COOL #2,264
- PHOTO-FINISH ≈ South Milwaukee…
- PRCP-UNK Rain n/a
- SWING-WIDE 50°F
- COMF-UNK Comfort n/a
- LOAD-HEAT 6,702 HDD
- STN-1 USC00119029
- BOOK-PART 4/6 fields
Nearest mean-temperature peer: South Milwaukee Wwtp, WI (+ 0 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every IL station list.
- Hot Mullen, NE 49°F
- Near Sidney, NE 49°F
- Waukegan (this station) 48°F
- Cold Cambridge, ID 48°F
- Near South Milwaukee…, WI 48°F
Climate Living Index · Waukegan
Waukegan: 42/100 · grade D
Waukegan publishes 3 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 3 missing weights rescale to 100.
PlainClimate-derived for Waukegan, not an official NOAA rating. Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Normal heat + freeze calendar | 145 calendar days | 50/100 · D |
| Frost-free season | 172 days/year | 43/100 · D |
| Annual temperature balance | 48.4°F · 19.1° from 67.5°F | 33/100 · F |
Waukegan · 2026-08-04 · NOAA NCEI Climate Normals · method .
National standing · heating-led station
Where Waukegan sits across the climate record
Available NOAA 1991–2020 fields for Waukegan are ranked only against stations that publish the same field, missing metrics stay blank rather than estimated.
- Annual temperature
- 33rd percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Seasonal temperature swing
- Wider than 80%
- Warmest-to-coldest month gap for Waukegan is large versus 6,861 complete station-years.
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 30°F (-1°C) | 16°F (-9°C) | 23°F (-5°C) | N/A | 28.6 | 0.0 |
| February | 34°F (1°C) | 18°F (-8°C) | 26°F (-3°C) | N/A | 24.6 | 0.0 |
| March | 44°F (7°C) | 27°F (-3°C) | 36°F (2°C) | N/A | 23.6 | 0.0 |
| April | 55°F (13°C) | 35°F (2°C) | 45°F (7°C) | N/A | 8.9 | 0.0 |
| May | 67°F (20°C) | 47°F (9°C) | 57°F (14°C) | N/A | 0.6 | 0.5 |
| June | 76°F (25°C) | 57°F (14°C) | 67°F (19°C) | N/A | 0.0 | 2.5 |
| July | 82°F (28°C) | 63°F (17°C) | 72°F (22°C) | N/A | 0.0 | 5.0 |
| August | 80°F (27°C) | 62°F (16°C) | 71°F (22°C) | N/A | 0.0 | 2.4 |
| September | 74°F (23°C) | 54°F (12°C) | 64°F (18°C) | N/A | 0.4 | 0.7 |
| October | 61°F (16°C) | 43°F (6°C) | 52°F (11°C) | N/A | 3.3 | 0.0 |
| November | 48°F (9°C) | 31°F (0°C) | 40°F (4°C) | N/A | 17.1 | 0.0 |
| December | 36°F (2°C) | 22°F (-6°C) | 29°F (-2°C) | N/A | 26.2 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 82°F around July 17, short of 90°F on every date, while 145 dates carry a normal low at or below freezing, the coldest 14°F near January 27.
The freezing stretch
The normal low stays at or below 32°F into April 6, then returns to freezing around November 14, covering 145 dates in all.
Derived from the normal daily minimum. This is a different measure from the 50%-probability frost dates shown elsewhere on this page, which come from NOAA’s frost product.
The widest day
April 23 carries the biggest normal gap between afternoon and dawn, 21°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Waukegan.
Where Waukegan Stands Nationally
Among the steadiest day-night climates ranked: even the widest normal daily swing holds to roughly 21°F.
Waukegan earns one nationally notable standing (outer quintile) against 6,860 NOAA 1991–2020 normals stations, middle-of-the-pack metrics stay silent here.
Monthly Precipitation
Average monthly rainfall
Frost Dates & Growing Season
First Fall Freeze
October 19
50% probability date
Last Spring Freeze
April 30
50% probability date
Growing Season
172 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
6,702
Higher = more heating needed
Cooling Degree Days
683
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside IL closest to Waukegan on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (48°F here).
- Alturas, CA 48°F · 0.0°F off
- Dunkirk, NY 48°F · 0.0°F off
- Falls Village, CT 48°F · 0.0°F off
- Haverhill, MA 48°F · 0.0°F off
Data-derived climate profile
How Waukegan's climate pattern fits together
heating led · mid swing
Waukegan's energy balance leans toward cold weather: 6,702 annual heating degree days against 683 for cooling. Its 49.7°F seasonal range still makes the monthly rows more useful than the annual average alone.
Waukegan's frost-free season lasts about 172 days, a middle-length window whose endpoints matter more than the annual average. It describes freeze probability, not year-specific planting conditions.
July and January mark the typical warm and cold ends of the calendar in Waukegan's middle-range seasonal profile. The measured spread is 49.7°F. The annual average is 48°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
A moisture-range label is withheld because Waukegan's annual precipitation total is unavailable. Monthly source values remain visible where NOAA provides them, and no annual amount is reconstructed from incomplete data.
These labels group NOAA 1991-2020 normals from Waukegan's primary station, so the winter figures are a thirty-year average and not a floor: a single hard season can run well below them. Treat each band as a descriptive range for Waukegan, not an official NOAA class or a year-ahead forecast.
Questions about Waukegan's climate
How cold does Waukegan get in winter? ▼
How much energy does heating and cooling require in Waukegan? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Waukegan's primary station: WAUKEGAN (USC00119029). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as an incorporated place (GEOID 1779293). Match rule for Waukegan: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.
On this page every temperature, precipitation, and derived score for Waukegan comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.