NYC Pest Complaint Monthly Outlook
July averages the most NYC 311 rodent complaints of any calendar month (4,057/year, 2023-2025); December the fewest (1,854). Non-rodent pest complaints (roaches, mice, insects) peak in August. But DOHMH field inspections — a direct-observation measure, not a resident report — find confirmed rat activity stays nearly flat all year (17.4%–19% fail rate), meaning reporting behavior swings more than actual activity does.
Calendar-month averages, 2023–2025 (three complete years). Pull date: 2026-07-04.
Which calendar month has the most pest complaints — averaged across years?
The Monthly Trends and Seasons pages track pest activity year over year and by four-month season. This page collapses 2023, 2024, and 2025 onto a single 12-month calendar to isolate the pure month-of-year signal — averaging out year-to-year noise (like the 2023 heat wave or the Rat Mitigation Zone program's gradual effect) to show the underlying annual rhythm.
NYC 311 rodent complaints (complaint_type='Rodent') peak in July at an average of 4,057 per month and bottom out in December at 1,854 — a 2.2× swing. Non-rodent pest complaints logged under NYC's "Unsanitary Condition" complaint type with a PESTS descriptor (covers cockroaches, mice, and general insect reports outside the dedicated Rodent category) peak later, in August (6,235/month), and bottom in February (4,039/month) — a smaller 1.5× swing than rodent complaints.
| Month | Rodent (avg/month) | Non-Rodent Pests — PESTS descriptor (avg/month) |
|---|---|---|
| January | 2,700 | 4,926 |
| February | 2,576 | 4,039 |
| March | 2,966 | 4,373 |
| April | 3,326 | 4,198 |
| May | 3,773 | 4,634 |
| June | 3,804 | 5,014 |
| July | 4,057 | 6,063 |
| August | 3,977 | 6,235 |
| September | 3,543 | 6,133 |
| October | 2,870 | 6,217 |
| November | 2,150 | 5,209 |
| December | 1,854 | 4,853 |
Source: NYC 311 Service Requests (erm2-nwe9). Rodent = complaint_type='Rodent'. Non-Rodent Pests = complaint_type='UNSANITARY CONDITION', descriptor='PESTS'. Each cell is the 3-year sum for that calendar month ÷ 3. Pull date: 2026-07-04.
Does confirmed rat activity swing seasonally the same way complaints do?
NYC's Department of Health and Mental Hygiene (DOHMH) runs proactive field inspections independent of resident 311 reports, logged in the Rodent Inspection dataset (p937-wjvj). Each inspection is marked Passed, Failed for Rat Activity, or several other outcomes. Because an inspector is physically checking a property for burrows, droppings, gnaw marks, and runways — not waiting for someone to call it in — the "Failed for Rat Activity" rate is a direct-observation measure of confirmed Rattus norvegicus (Norway rat, NYC's dominant urban rodent species) activity, not a reporting proxy.
Averaged by calendar month across 2023-2025, that fail rate ranges only from 17.4% (a low point shared by June and December) to 19% (a high point shared by April and November) — a 1.6-percentage-point band. Compare that to the 2.2× swing in 311 rodent complaint volume over the same window and the same three years. The gap between a near-flat confirmed-activity signal and a large complaint-volume swing supports the reading on the Seasons page: NYC's rat population does not shrink in winter, it goes indoors and underground — into basements, subway tunnels, and sewers — where it is less visible to residents and less likely to trigger a 311 call, even though it hasn't gone away.
| Month | Fail rate (confirmed rat activity) |
|---|---|
| January | 18.7% |
| February | 18.4% |
| March | 18.3% |
| April | 19% |
| May | 18% |
| June | 17.4% |
| July | 17.7% |
| August | 17.6% |
| September | 18.5% |
| October | 18.6% |
| November | 19% |
| December | 17.4% |
Source: DOHMH Rodent Inspection (p937-wjvj). Fail rate = "Failed for Rat Activity" ÷ all inspection results that month, 3-year sums (2023-2025) ÷ 3-year totals. Pull date: 2026-07-04.
Frequently asked questions
Which month has the most NYC rat complaints?
July averages 4,057 311 rodent complaints per year across 2023-2025 — the highest of any calendar month. August is a close second at 3,977.
Which month has the fewest NYC rat complaints?
December averages 1,854 rodent complaints, the lowest calendar month in the 2023-2025 dataset — about 2.2× fewer than the July peak.
Does confirmed rat activity found by DOHMH inspectors follow the same seasonal swing as 311 complaints?
No. DOHMH Rodent Inspection field results (dataset p937-wjvj) show a "Failed for Rat Activity" rate that stays within a 1.6-percentage-point band all year (17.4%–19%), compared to a 2.2× swing in 311 complaint volume. Confirmed activity is close to flat; what changes seasonally is how often residents notice and report it.
What month has the highest overall pest complaint volume, including non-rodent pests?
August, at 6,235 average PESTS-descriptor complaints (NYC 311 complaint_type='UNSANITARY CONDITION', descriptor='PESTS' — covers roaches, mice, and other insect reports outside the dedicated Rodent category). The low is February at 4,039, a 1.5× swing.
Is 311 complaint data a reliable way to measure actual pest population?
It's a proxy, not a census. 311 volume reflects reporting behavior — which is itself seasonal (people notice pests more in warm weather, windows open, outdoor activity increases) — layered on top of whatever the true underlying pest population is doing. The DOHMH inspection fail-rate, based on direct on-site observation rather than resident reports, is the closer of the two measures to an actual activity signal.
Complaint data: NYC 311 Service Requests, sourced via the NYC Open Data portal (Socrata platform). Inspection data: NYC DOHMH. Neither dataset is produced by Urban Pest Watch — see the Methodology page for query definitions and the About the Data page for known limitations. For general rodent-control guidance, see the CDC.