Hopefully you have plenty of mosquito repellent stocked up. We may be just a few days from the start of fall, but mosquito activity has been and will continue to be very high to extreme. Mosquito season in northern Indiana and most of Michigan typically begins around May 1st and begins to wind down in early September once cooler weather starts becoming the norm. When the temperature drops below 55° or so, mosquito activity drops considerably. In Michiana, we've had several nights with sub-55° temperatures thus far in September. That put a dent in mosquito activity...until this week.
Thanks to a wetter-than-normal August and unusually hot mid-September temperatures that have been in the 80s, mosquito activity levels have soared. They will likely remain in the "very high" and "extreme" categories for at least the next week as temperatures are forecast to stay in the 80s through possibly Friday. Not only do we have the heat and August rain supporting high mosquito activity, but it's humid as well. Mosquitoes flourish when high humidity is paired with temperatures between 75° and 90°.
In other words, the conditions in Michiana right now are nearly ideal for mosquito levels to pretty much be disgusting. If we see any rain at all Tuesday, Wednesday or Thursday, expect that to only worsen the problem. Mosquitoes love moisture and standing water. Keep that in mind with the potential for rain and thunderstorms late this week and this weekend. Unfortunately, the pests will likely remain at least highly active into next week. The good news? Overnight temperatures are forecast to drop into the lower and middle 50s by Friday night. If we see multiple nights below 55°, mosquito activity could drop considerably. Mosquito season is deemed over after a frost or freeze occurs. South Bend typically sees its first frosty night by October 19th or so.
