Weekly Update – July 6th – Have We Reached the Mosquito Peak?
July 6, 2026
Weekly Update – July 21st – Mosquitoes on the Decline
July 21, 2026
Mosquito numbers ticked up again in Priority 1 areas and declined in Priority 2.
We are likely experiencing the highest number of mosquitoes we will see in the metro this summer. And it's not that many.
Last week our lab predicted that the number of cattail mosquitoes had peaked for the year and that projections seems to be accurate, though they are still out in abundance. The cattail mosquito surge combined with some early July rain led to the most mosquitoes in Priority 1 zones of the year so far, though still well below normal. There is no rain in the forecast for this week and the cattail mosquito numbers will only go down from here on out, so we are currently experiencing what is likely to be the high point in the mosquito season in terms of abundance.
Now that we are more than half way through the mosquito season of 2026 this is looking more like the dry years of 2021-2023 than 2024 or 2025. Mosquito numbers are significantly below the 10-year average, but if you zoom in and do a 5-year average it looks more in line, due to 2021-23 experiencing drought or abnormally dry conditions:
Mosquito numbers are actually above the 5-year average when the drought years are more heavily weighted.
Minnesota has been marked by unusual weather patterns for a while now and a trained climatologist would be better equipped to know whether the fact that 4 of the past 6 years have been unusually dry is a blip or a trend, but we can report that the fact that these weather trends have happened makes an impact on the mosquito populations.
The most mosquitoes are still found in the outer areas of the District. Northern Washington and Northeastern Anoka County continue to be the hot spots with scattered abundance in other counties. Here are this week's maps:
Deer Tick Numbers on the Decline as Well
In addition to mosquitoes being on the decline from here on out, deer tick numbers are trending down as well, which is in line for a typical season. According to MMCD Entomologist, Dr. Scott Larson, "We've passed the normal peak of nymphal blacklegged ticks now that we are basically in mid-July. People should be encountering fewer and fewer of these ticks as the season progresses. The next worrisome peak will occur in the fall (mid-October into November) when the adult blacklegged ticks will be actively searching for hosts before the winter."
Deer ticks seek a bloodmeal for each life cycle stage and their full metamorphosis takes multiple years to complete. Larval tick numbers can help project the number of nymphs and adults may be active in coming seasons. More information about this year's tick surveillance data will be available at the end of the year.
Image from CDC.gov
A technician demonstrating the "sucomatic" - an aspirator trap for collecting mosquitoes.
New West Nile Virus Positive Mosquitoes Found in Hennepin, Ramsey, and Anoka Counties
A few weeks ago we talked about the elevating risk of West Nile virus as we head into late summer months. Last week five new mosquito pools tested positive for West Nile virus in the Twin Cities, but all of them were in counties and near locations where we had already found positive samples this year. 3 positive samples came from Hennepin County and 1 each from Ramsey and Anoka Counties.
Human risk of West Nile virus transmission peaks in August, so it is still early to definitively say that this will be a low year for West Nile virus transmission, but it's trending much lower than 2025, which was a record year for human cases in the State. The areas that have now returned multiple positive samples will receive additional surveillance and may receive adult mosquito treatments in the coming weeks.
Upcoming Events
Come out and see staff from the Metropolitan Mosquito Control District at one of these upcoming events:
- Thursday, July 16th - Sunday, July 19th - Ramsey County Fair in Maplewood
- Thursday, July 16th - Concert in the Park in Shorewood
- Thursday, July 16th - Maple Grove Days Parade in Maple Grove
- Friday, July 17th - Arden Hills 75th Anniversary Celebration in Arden Hills
- Sunday, July 19th - Raspberry Festival Parade in Hopkins
- Tuesday, July 21st - Sunday, July 26th - Anoka County Fair in Anoka
- Wednesday, July 22nd - Sunday, July 26th - Scott County Fair in Jordan
Would you like MMCD to come to your event or speak to your group? E-mail Alex Carlson!
Video of the Week - Tick Surveillance at MMCD
Learn about the tick species that we have in Minnesota and how MMCD goes about collecting and studying ticks.
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