Your Inspection Report

Is There a Pest Season? Month by Month in Salt Lake County Inspections

Written for: Restaurant owners and managers, kitchen managers planning the year

Parts of this page marked Professional synthesis, not law are a Board Certified Entomologist's reading of published records. They are not legal rules, they are not legal advice, and they are written to read the same for an owner, a customer, or either side's counsel.

Everyone in pest control has a story about mice in October and flies in July. This page tests the story against two years of county inspection records instead of repeating it. The numbers are routine inspections, county-wide, by calendar month; no restaurant is identified (method).

Pest lines by month

The share runs between about 12 and 19 percent all year. The high months are August and September; the low months are November and December. The spread is real but modest: the difference between the highest month and the lowest is about 7 points, roughly one inspection in fifteen.

Flies are the season

Looking only at lines where the inspector named a pest, flies are the one pest with a clear season: 32 inspections in August and 26 in September, 10 in October, and below this site’s publication floor of 10 inspections in every other month. Cockroaches are the other pest that clears the floor, but without a season: 10 or 11 inspections in April and from June through September, 16 in October, and below the floor in every other month. That flat line is the point: cockroaches ride in on deliveries all year. The fly peak is the whole seasonal signal in the inspection record. It matches the biology: house flies and blow flies breed fastest in warm weather, and fruit flies ride in on late-summer produce (flies, fruit flies).

What the data do not show

Monthly counts for rodents and ants are below the publication floor in every month, and cockroach counts sit near it without a peak, so this site makes no seasonal claim about any of them. In particular, the familiar “mice come in when it gets cold” pattern does not show up in the inspection record at a level this site will publish. That does not prove it is false; mice do move indoors as temperatures fall, and a kitchen’s own records are a better test than an inspector’s visit schedule. It means the inspection data are not evidence for it, and this site says only what its data show.

Cockroach lines, for what it is worth, appear in every month of the year. A German cockroach population lives indoors, near heat and water, and has no season (German cockroach).

What this means for a manager

Professional synthesis, not law.

1. Plan the fly work for July. Drain cleaning, door sweeps and screens, dumpster lids and the schedule for emptying it, and the placement of any insect light (never over food or prep; that is its own citation) should be done before August, not during it.
2. Keep the rest of the program flat. Because pest lines are nearly as common in February as in August, a program that only runs in summer is a program that misses half the year’s findings.
3. Check deliveries all year. The Delivery Inspection Card is the one habit that affects cockroaches and stored-product pests, which have no season.