Summer 2024 was one of Milwaukee’s warmest in history, setting multiple records

September is here, meaning meteorological summer is officially over.

But, before we welcome cooler weather, colorful leaves and pumpkin spice, let’s recap this summer’s weather.

Summer in Milwaukee had average temperatures slightly above normal, with multiple periods of record-setting, well-above-normal temps driving up the overall average, the Milwaukee-Sullivan National Weather Service reported.

According to the NWS, this summer ― defined by the weather service as June 1 through Aug. 31 ― was Milwaukee’s 19th-warmest, per Weather Service data dating to the 1870s.

The summer’s three-month average temperature of 71.8 degrees was 0.7 degrees warmer than the 30-year climate normal. Milwaukee’s warmest summer ever was in 2012, when the three-month average temperature was 74.1 degrees. Five of the 10 warmest summers in the city’s history have occurred since 2010, according to NWS data.

How warm was summer 2024 in Milwaukee?

Though the summer’s average temperature wasn’t too far off normal, multiple periods of extreme heat set daily temperature records for Milwaukee.

The summer’s hottest recorded temperature in the city was 94 degrees, on June 17 and 18 and again on Aug. 26 and 27. This set Milwaukee’s June 17 record high and came close to the city’s Aug. 26 record high of 96 degrees, set in 1953.

Milwaukee also had three record-warm low temperatures this summer: 78 degrees on June 18 and Aug. 26 and 75 degrees on Aug. 27. Due to heat indices around 100 degrees, a heat advisory was issued in Milwaukee County on Aug. 26, and an excessive heat warning was in effect the next day.

June 2024 was Milwaukee’s eighth-warmest June on record, according to NWS data. The month’s average recorded temperature of 70.4 degrees was nearly 3 degrees warmer than the city’s 30-year normal. Meanwhile, this summer was only the 46th-warmest July on record, with average temps actually 0.8 below normal. According to an NWS Facebook post, this August had an average temp of 72.3 degrees, identical to the 30-year normal.

What does Milwaukee’s warm summer mean for this fall and winter?

According to the National Oceanic and Atmospheric Administration’s long-range forecast, Wisconsin is expected to see above-normal temperatures this fall, with chances highest in the far-southeastern portion of the state, including the Milwaukee area.

By winter, a naturally occurring weather phenomenon known as La Niña is expected to bring a colder and snowier-than-normal winter to the northern U.S. La Niña is caused by the cooling of water temperatures in the central Pacific Ocean to below average for several months.

According to the NOAA, these cold waters in the Pacific push the polar jet stream northward. This often brings drought to the southern U.S. and heavy rains in the northwest and Canada. La Niña tends to produce colder winter temperatures in the northern U.S. and warmer temps in the south. It can also generate a more active hurricane season.

NOAA issued a La Niña watch in mid-June, predicting La Niña conditions to emerge between September and November and persist through the winter.

Last winter, Milwaukee and Wisconsin strongly experienced the effects of El Niño, the opposite of La Niña. During an El Niño year, warmer-than-average temperatures in the Pacific bring warmer, drier winter conditions to the northern U.S. Numerous local weather experts and meteorologists told the Journal Sentinel that El Niño was the main culprit behind Wisconsin’s record-setting warm winter.

More: This has been one of Milwaukee’s warmest and wettest summers. Here’s why