Pest Control’s August Peak: A Year of California Treatment Reports, Month by Month

Measuring the season in work, not in staff

Our analysis of pest control employment by month measured the industry’s seasonal swing in payroll: 141,809 people nationally in January against 159,456 in July. Payroll is an indirect measure. Firms hold staff through the slow months, add overtime in the busy ones and hire seasonally only at the margin.

California is the one place where the work itself can be counted month by month. Licensed businesses file a monthly summary report for each pesticide product they use in each county, and the state publishes every report. We counted 498,927 structural pest control reports for 2022 and 512,367 for 2023 and placed each in its month.

This is a California calendar. It shows how the work is distributed across the year in one large, mild-climate market, which is a different question from how pest pressure changes with warming, covered in our report on how the pest season is lengthening.

The shape of the year

Source: California Department of Pesticide Regulation, Pesticide Use Reports 2022 and 2023, site code 10, distinct monthly summary reports. Author calculation.

What it means. The year has one broad hump. Work climbs steadily from January to a peak in August, holds through September and falls away from October. August had 1.30 times as many reports as January in 2022 and 1.33 times in 2023. The six months from May to October hold 53.9 percent of the year’s reports in 2022 and 54.4 percent in 2023. There is no spring spike and no second peak.

What limits it. A report covers one product, one county and one month for one business, so the count measures how many business-product combinations were active, not hours worked or homes treated. A firm that treats twice as many homes with the same product in August files the same single report. The count therefore understates the true swing in volume, if anything.

Workload moves five to eight times as much as payroll

The Bureau of Labor Statistics publishes monthly employment for pest control firms, NAICS 561710, in California. Setting it beside the report count, both indexed to January, shows how the industry absorbs the season.

Sources: California Pesticide Use Reports 2022 and 2023, site code 10; US Bureau of Labor Statistics, Quarterly Census of Employment and Wages, NAICS 561710 Exterminating and Pest Control Services, California, private ownership, monthly employment. Author calculation.

What it means. California’s pest control firms carry a work peak of about 30 percent on a payroll that rises by 4 to 7 percent. The difference has to come from somewhere: longer days, overtime, denser routes or slack in the winter months. The data do not say which, but they put a number on the operating problem every California owner manages.

What limits it. Employment counts people on the payroll in the pay period including the 12th of the month, not hours. The two series cover slightly different populations: the employment series covers firms classified to pest control, while the reports cover every licensed business doing structural work, including some classified to other industries. California’s mild climate likely makes its swing smaller than in colder states, where our employment analysis found far larger payroll swings.

Which compounds follow the season, and which ignore it

The overall curve averages very different patterns. Measuring each active ingredient’s busiest month against its quietest separates the seasonal products from the steady ones.

Source: California Pesticide Use Reports 2022 and 2023, site code 10, monthly reports naming each active ingredient. Ratio of the month with the most reports to the month with the fewest. The full list of 30 ingredients is in the CSV. Author calculation.

What it means. Three groups emerge, and they hold in both years. Phenothrin and prallethrin, two pyrethroids, more than double between their quietest month and August. Fipronil roughly doubles. At the other end, bifenthrin, which is used in more California structural applications than any other ingredient, is close to flat, and so are all three rodenticides. The rodenticides are the only group whose busiest months fall in autumn and winter: October for diphacinone, November or December for bromethalin, January or February for cholecalciferol.

What limits it. A flat line is consistent with year-round service contracts, such as scheduled bait-station checks and recurring perimeter treatments, but these data record use, not contract type, so that explanation is an inference. The ratio uses only two months of the twelve and is sensitive to a single unusual month in smaller series.

The rodenticide calendar barely bends

Combining all seven rodenticides recorded in structural use, the monthly share of reports ranged only from 8.1 to 8.5 percent in 2022 and from 8.1 to 8.8 percent in 2023. A perfectly even year would put 8.3 percent in every month. In 2022 the highest months were August and October, at 8.5 percent each, with November close behind. In 2023 the highest was October, at 8.8 percent, followed by December and September at 8.7 percent.

What it means. For an operator, rodent work is the line of business that holds its volume through the winter, when total structural reports fall to about three quarters of their August level. The individual rodenticides with a clear peak put it in autumn or winter, not summer.

What limits it. Report counts are not rodent activity. A business that services the same bait stations every month files a report every month whether rodent pressure is high or low. The flatness may describe the service model as much as the pest.

Three checks on the calendar

1. Replication across two years

Definition. Whether the shape repeats when the whole calculation is run on an independent year.

Method. 2022 and 2023 were parsed separately, from archives with different internal layouts and different date formats.

Result. August is the peak and January the trough in both years. The August-to-January ratio is 1.30 and 1.33. The 13 compounds in the table rank in a similar order in both years.

Limitations. Two years is a replication, not a stable average.

2. Reports against applications

Definition. Whether the season looks the same when measured in applications, the count each report states, instead of reports.

Method. Summed the application-count field by month.

Result. The direction agrees: May to October holds 53.8 percent of 2022 applications and 57.0 percent of 2023 applications, against 53.9 and 54.4 percent of reports. But the application series is lumpy. A small number of reports each state thousands of applications, and in 2023 they push June above August. We use reports as the headline measure because they repeat cleanly between years.

Limitations. Neither measure is a count of customer visits, which the data do not record.

3. Date integrity

Definition. Whether the month assigned to each report is real.

Method. Checked every date. The 2022 files use a month-first format and the 2023 files a day-month-year format, which a naive parser misreads.

Result. No unparseable dates in either year. 99.99 percent of reports are dated the first of the month, which the department’s documentation describes as the default day for monthly summaries. Only the month carries information, and only the month is used here.

Limitations. The month is the month of use as reported by the business. Reports filed late or corrected are as the department published them.

Download the data

The tables in this report are published as CSV files under a Creative Commons Attribution 4.0 licence. You may republish, remix and build on them, including commercially, with attribution to The Pest Control Brief and a link to this page.

• Monthly reports, applications and employment, California, 2022 and 2023 (CSV, 24 rows)
• Busiest and quietest months for 30 active ingredients, 2022 and 2023 (CSV, 30 rows)

How to cite this report

The Pest Control Brief, “Pest Control's August Peak: A Year of California Treatment Reports, Month by Month”, 2 October 2026. https://thepestcontrolbrief.com/pest-control-workload-by-month/

References

1. California Department of Pesticide Regulation. Pesticide Use Report annual archives for 2022 and 2023. files.cdpr.ca.gov/pub/outgoing/pur_archives/. Accessed 2 October 2026.
2. California Department of Pesticide Regulation. PUR field definitions, readme_excel.xlsx, supplied inside the 2023 archive. Source of the definitions of the applic_dt and applic_cnt fields and of monthly summary reporting for non-agricultural use.
3. US Bureau of Labor Statistics. Quarterly Census of Employment and Wages, industry 561710, 2022 and 2023, quarters 1 to 4. data.bls.gov/cew/data/api/2022/1/industry/561710.csv (other quarters by the same pattern). California, area 06000, private ownership. Accessed 2 October 2026.
4. The Pest Control Brief. The industry’s July: pest control employment by month. thepestcontrolbrief.com/pest-control-seasonality. Source of the national employment figures.

How the calendar was built

Source and scope. Every California Pesticide Use Report record for 2022 and 2023 with site code 10, Structural Pest Control, from the 58 county use files in each year’s archive.

Unit. A distinct report, identified by its use number within a county file. A product with several active ingredients appears as several rows of one report and is counted once in the totals. In the ingredient table, a report is counted once for each ingredient it names.

Month. Taken from the application date field, parsed separately for each year’s format.

Employment. Monthly employment from the three monthly columns of each quarterly file, California statewide, private ownership, NAICS 561710.

Limitations. California only. Two years. Reports measure active business-product combinations, not visits or hours. The employment and report series cover overlapping but not identical sets of businesses.

Last reviewed: 2 October 2026.

For operators and reporters

Figures worth quoting

1. California structural pest control filed about 30 percent more treatment reports in August than in January, in both 2022 and 2023.
2. Employment at California pest control firms rose 3.6 percent from January to August 2022, against a 29.9 percent rise in reports.
3. May to October holds 54 percent of the year’s structural pest control reports.
4. Rodenticide work is nearly flat across the year and peaks in autumn or winter, the opposite of insecticide work.
5. Phenothrin and prallethrin more than double between their quietest month and August.

Caveats that travel with them

California only. A report covers a product, a county and a month for one business, so the count is a conservative measure of volume. Employment counts heads, not hours.

Press summary

California’s pest control work peaks in August at about 30 percent above January, while the industry’s payroll barely moves, according to an analysis of state pesticide use reports by The Pest Control Brief. Across 1,011,294 structural pest control reports filed in 2022 and 2023, work rose steadily from a January low to an August high in both years. Employment at California pest control firms rose only 3.6 to 6.6 percent over the same months. Rodenticide work ran against the trend, staying nearly flat and peaking in autumn and winter.

Headlines editors could use

1. California pest control works 30 percent harder in August, with almost the same staff
2. Rodent work is pest control’s winter business
3. The month-by-month calendar of a million pest control reports
4. Why pest control’s summer peak never shows up in its payroll

What readers ask

What is the busiest month for pest control?

In California structural pest control, August, in both 2022 and 2023, with about 9.4 to 9.5 percent of the year’s reports. January is the quietest at about 7.2 percent.

How much busier is summer than winter?

August had 1.30 times as many reports as January in 2022 and 1.33 times in 2023. May to October holds about 54 percent of the year.

Do pest control companies hire more staff in summer?

Only slightly in California. Employment at pest control firms rose 3.6 percent from January to August 2022 and 6.6 percent in 2023, far less than the workload.

Is rodent control seasonal?

Barely, on these data. Rodenticide reports are nearly flat through the year and peak in autumn or winter. That may reflect scheduled bait-station servicing as much as rodent activity.

Which treatments are the most seasonal?

Phenothrin and prallethrin, two pyrethroids, more than double from their quietest month to August. Fipronil roughly doubles.

Is this the same in other states?

Not necessarily. California’s climate is mild. Our national employment analysis found much larger payroll swings in colder states, which suggests larger workload swings too, but no other state publishes the reports needed to measure it.

Why count reports rather than applications?

Because reports give a consistent calendar in both years, while application counts are distorted by a small number of reports that each state thousands of applications. Both measures agree on the direction.

Where can I get the data?

From the California Department of Pesticide Regulation’s public archive. Our monthly tables are published as CSV files above.