July weather forecast
Illinois, USA

July stands as the pinnacle of summer in Illinois, delivering the year's warmest temperatures and intense solar radiation. In the northern stretches, close to Wisconsin, daytime temperatures usually hover in the low to mid-80s°F. However, the southern territories, neighboring Kentucky, often experience the mercury rising to the upper 80s°F (around 87.8°F (31°C)), with occasional forays into the 90s°F higher than suburban locales, exemplifying the urban heat island effect.

Nighttime in July provides limited respite from the day's heat. Lows often remain in the mid to upper 60s°F across the state. The nights, though warmer, set the stage for a myriad of summer activities under the starlit sky.

Comparing July to June, there's a discernible uptick in both temperature and humidity. Thunderstorms, fueled by the heat and moisture, become more frequent, especially in the latter parts of the day. As July concludes, its reign as the hottest month of the year remains uncontested, paving the way for the slightly more temperate conditions of August.

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• Chicago - July »
  As June transitions into July in Chicago, a subtle temperature shift is observed, with average highs adjusting from an agreeable 70.5°F (21.4°C) to a warm 77.4°F (25.2°C). In Chicago in July, during 18.5 rainfall days, 4.21" (107mm) of precipitation is typically accumulated.
• Aurora - July »
  The months with the highest humidity in Aurora are January, February and July, with an average relative humidity of 83%. July is the month when Aurora sees the average highest temperatures, with a high of 81°F (27.2°C) and a low of 64°F (17.8°C).
• Rockford - July »
  As mid-summer arrives in Rockford, July becomes the warmest month of the year with the highest monthly average maximum temperature coming in at 79.9°F (26.6°C). On the last day of July, in Rockford sunrise is at 5:48 am and sunset at 8:16 pm CDT.
• Joliet - July »
  On the last day of July, in Joliet sunrise is at 5:46 am and sunset at 8:10 pm CDT. Joliet witnesses the warmest weather in July, with temperatures averaging a high of 81.3°F (27.4°C) and a low of 64.8°F (18.2°C).
• Naperville - July »
  The months with the most sunshine in Naperville are July and August, with an average of 10h of sunshine. In Naperville, July is the month with the highest recorded average temperatures, measuring a high of 81.7°F (27.6°C) and a low of 65.1°F (18.4°C).
• Springfield - July »
  With an average relative humidity of 84%, July is the most humid month in Springfield. In Springfield in July, it is raining for 15.8 days, with typically 2.09" (53mm) of accumulated precipitation.
• Peoria - July »
  July is the month when Peoria sees the average highest temperatures, with a high of 82°F (27.8°C) and a low of 65.3°F (18.5°C). The most humid month in Peoria is July, with an average relative humidity of 84%.
• Elgin - July »
  July is the month when Elgin, Illinois, experiences its warmest temperatures, averaging a high of 80.6°F (27°C) and a low of 63.9°F (17.7°C). The months with the highest UV index in Elgin, Illinois, are July and August, with an average maximum UV index of 6.
• Waukegan - July »
  July and August, with an average of 10.5h of sunshine, are months with the most sunshine in Waukegan. The months with the highest UV index in Waukegan are July and August, with an average maximum UV index of 6.
• Champaign - July »
  With an average relative humidity of 85%, July is the most humid month in Champaign, Illinois. In Champaign, July is the month with the highest recorded average temperatures, measuring a high of 81.1°F (27.3°C) and a low of 65.1°F (18.4°C).
• Cicero - July »
  July, with average temperatures reaching a high of 79.7°F (26.5°C) and a low of 67.5°F (19.7°C), is the warmest month in Cicero, Illinois. On the last day of July, in Cicero sunrise is at 5:44 am and sunset at 8:10 pm CDT.
• Bloomington - July »
  With an average relative humidity of 85%, July is the most humid month in Bloomington. With an average relative humidity of 85%, July is the most humid month in Bloomington.