Edmonton
How bad are the mosquitoes?
The City of Edmonton empties a network of CO2 traps every week and counts what is in them. This takes the traps it publishes and asks the only question that matters: is this worse than normal for the time of year?
No count has been published for 45 days
The traps are still being emptied — the City runs the programme from late April to the end of September — but the open dataset behind this page has not been updated. It normally runs one to three weeks behind the trap date, and it does sometimes stall mid-season. Rather than dress up an old number as this week’s, here is exactly what the last published count was.
3,828 female mosquitoes per trap, averaged over the 8 traps that reported on July 9, 2026.
The 2026 season so far
Each bar is one week’s trap collection, next to what that week of the year usually brings. The comparison is the median of the same week across earlier seasons, so a late spring or an early peak shows up as a gap rather than being averaged away.
View as table
| Category | 2026 | Usual for that week |
|---|---|---|
| May 7 | 2 | 2 |
| May 14 | 2 | 2 |
| May 21 | 2 | 7 |
| May 28 | 26 | 10 |
| June 4 | 6 | 15 |
| June 11 | 83 | 23 |
| June 18 | 153 | 39 |
| June 25 | 1071 | 62 |
| July 2 | 3055 | 121 |
| July 9 | 3828 | 271 |
What was in the traps
Females caught on July 9, 2026, by genus.
- Aedes30,260 (99%)
- Coquillettidia144 (0.5%)
- Culex136 (0.4%)
- Culiseta80 (0.3%)
How this is measured
The City monitors more than forty trap sites. The dataset it publishes openly contains six to nine of them, so the average here is smaller than the figure the City and the news quote for the same week — both are counting real traps, just not the same ones. That is why the verdict above is a comparison rather than a count: a ratio against the same week in earlier years holds up even though the trap network behind it changes.
Only females are counted, because only females bite. Traps that caught nothing are still counted as traps, so a quiet week reads as quiet instead of disappearing.
A collection reflects the week before the traps were emptied, and the City publishes with a lag of one to three weeks. This page works out the age of the newest count and says so; past 17 days it stops presenting it as the current picture.
Contains information licensed under the Open Government Licence – City of Edmonton. Trap counts from the City’s CO2 Mosquito Trap Data; the City’s own dashboards and programme details are on its mosquitoes page. The index, the banding and the comparison are ours, not the City’s, and nothing here should be read as the City endorsing them. Planning an evening outdoors? Check the forecast.