Historical weather data, all-time temperature records, and monthly climate averages for South Lyon, MI. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5th in South Lyon swings wide — this date has seen a 76° scorcher back in 1929 and a brutal 13° low as recently as 2016. On average, expect a cool 50° high and a frosty 31° overnight. There's nearly a coin-flip chance of precipitation, with a 1-in-9 shot it comes down as snow.
South Lyon doesn't mess around at the extremes — the thermometer has hit 104° in the summer of 1934 and plunged to -27° in February 2015, a 131-degree swing over the historical record. A single June day in 1968 dumped 5.86 inches of rain, and December 1974 brought 16 inches of snow in one storm.
Summers are warm and brief, peaking mid-July with average highs of 83°, while January and February barely crack the freezing mark with highs in the low 30s. Spring is the wettest stretch — the first two weeks of May average nearly an inch of precipitation per week. Plan beach days for July and August; plan for anything in April.