Most seasonality advice assumes a four-season climate and a heating season. Applied to Florida it is nonsense, and applied to Southern California it is close to it.
Here is what the year actually looks like in the three states we work in most.
Florida
Baseline is high and flat. Air conditioning is not a comfort purchase here; it is habitability, and it runs closer to year-round than anywhere else. That flattens the curve a Midwestern HVAC company builds their year around.
The spike is an event, not a date. June through November nominally, with the weight in August and September, and it arrives with a storm rather than a calendar page.
The money is in the tail. Six to eighteen months after a significant event, when claims settle and deferred work gets done. Most competitors have cut budgets by then.
We went through the budget shape in hurricane season and Florida contractor advertising.
New York
The sharpest curve of the three. Winter is a genuine demand event for heating and plumbing, and a hard stop for exterior work. Spring produces a compressed rush of everything deferred since November.
Upstate and downstate differ. Upstate's winter is longer and more severe; downstate's is milder and its spring bounce is earlier. Running one statewide budget through February means overpaying for exterior-work clicks nobody is booking. The two are separate markets.
Emergency dominates in season. Which will eat a shared budget entirely if emergency and planned work are not separated into different campaigns.
California
The flattest curve, and the most misread. Southern California barely has a heating season, which means the demand pattern is driven by weather events — a rain event after a dry spell produces roof calls — rather than by temperature.
Fire season is its own thing. Late summer into autumn, with genuine restoration demand afterwards and the same ethical questions that post-storm work raises in Florida.
Inland and coastal differ more than people expect. The Inland Empire's summer is a real air conditioning season in a way the coast's is not. The three Southern California markets are genuinely different.
There is no national seasonal calendar. There is your trade, in your metro, with your weather, and last year's own data beats any published curve.
What to do with this
Use your own history first. Two years of your own booking data beats any industry chart, because it already contains your trade, your market and your customer.
Keep a floor year-round. Accounts that go fully dark and restart spend the first fortnight relearning what they already knew. A small always-on budget keeps the pixel and the audiences warm.
Build lists in the quiet months. The cheapest in-season lead is someone who already knows your name. Off-season is for inexpensive reach, not for direct response.
Separate emergency from planned everywhere. This is the one rule that holds in all three states. Emergency converts instantly and will consume the budget from planned work, which has better margin and a longer cycle.
If your budget has been flat across the year, splitting it by season using your own booking history is usually worth more than any targeting change.