Chicago · Month comparison

August vs October

October ranks #1 overall vs August at #8. Chicago Marathon weekend (second Sun in Oct) — 50,000 runners through every neighbourhood.

Blue Angels flying past Chicago skyline

August

#8 of 12 months

Strong option

Air & Water Show fills the lakefront sky — Blue Angels rip past Navy Pier at 500mph.

  • ↑Chicago Air & Water Show (mid-Aug) — free, 2 million on the lakefront
  • ↑Lake at 21°C — its warmest of the year
Chicago Marathon runners through downtown

October

#1 of 12 months

Best match

Chicago Marathon weekend (second Sun in Oct) — 50,000 runners through every neighbourhood.

  • ↑Chicago Marathon — World Marathon Majors event, the entire city stops to watch
  • ↑Lincoln Park and the lakefront in red-and-gold maple
FactorAugustOctober
Weather score
8
9
Value score
3
7
Crowd score
3
7
Events score
9
9
Atmosphere
10
10
Avg high temp28°C17°C
Monthly rain100mm80mm
Daily sunshine10hrs7hrs

August trade-offs

  • ↓Lake-effect humidity makes 28°C feel oppressive afternoons
  • ↓Hotel rates still peak; festival overlap (Air Show, Lollapalooza recovery)

October trade-offs

  • ↓Marathon weekend hotel rates double; Loop streets closed
  • ↓First frost and possible early snow late month
See all 12 months for Chicago →August in detail →October in detail →
Scores compare months within Chicago. Climate data: Open Meteo ERA5 30-year normals (1991–2020). Methodology →