Use Google Ads seasonality adjustments only for a forecast cold snap of 1 to 7 days, only in campaigns on Target CPA, Target ROAS or Performance Max, and only when your techs have open slots to fill. Let Smart Bidding handle the gradual slide from fall into heating season on its own.
That rule is narrow on purpose. The feature doesn’t raise bids the way a manual bump does. It tells Smart Bidding to expect a short, sharp change in conversion rate, and if you overestimate that change or aim it at a schedule that’s already full, you pay more per click for jobs you can’t run.
Below is how to decide whether the first freeze of the season deserves an adjustment, which tool to use when it doesn’t, and how to size the percentage from your own booked-job data.
Key takeaways
- It’s a conversion rate signal, not a bid boost. Google describes the feature as scheduling a conversion rate adjustment, so size it from expected conversion rate change, not expected CPC increases.
- Eligibility is narrower than most people assume. Search, Shopping, Demand Gen and Display campaigns qualify only on Target CPA or Target ROAS, while Performance Max qualifies on any bid strategy.
- Match the tool to the problem. Budget-limited campaigns need a seasonal budget adjustment, broken tracking needs a data exclusion, and a full dispatch board needs no change at all.
- Keep it short. Google says adjustments work best for 1 to 7 days and may not work as well past 14 days.
- Capacity decides first. If the schedule is booked out for the forecast window, more demand only raises your cost per booked job.
What a seasonality adjustment actually tells Smart Bidding
A seasonality adjustment schedules a temporary change in expected conversion rate for Smart Bidding. It is not a budget increase, a manual bid raise, or a CPC forecast.
Google’s Help documentation describes the feature as “scheduling a conversion rate adjustment” for a set window. You tell the system, in effect, that clicks during these dates will convert at a higher (or lower) rate than recent history suggests, and Smart Bidding bids accordingly. Google’s own example is a +50% adjustment for a 3-day sale.
When the window ends, bids go back to normal. Google is explicit that you don’t need to add a negative adjustment afterward to undo it.
Google’s own guardrails
Google recommends using the feature only “if you expect major changes to conversion rates, because Smart Bidding already manages seasonal events.” It also says adjustments work best for events of 1 to 7 days and may not work as well beyond 14 days.
That warning matters for HVAC. The common mistake is to set the percentage based on how much CPCs will rise during a cold spell. CPC is an output of the auction. The input Google is asking for is how much more likely a click is to turn into a conversion.
Why a cold snap fits and the heating season doesn’t
The gradual shift from shoulder season into heating season shows up week by week in your conversion data, and Smart Bidding learns from that trend as it happens. A three-week ramp is exactly the kind of seasonality Google says the system already handles.
A first hard freeze is different. It lands on a specific few days set by the forecast, not by the calendar, and conversion rates can jump faster than recent history would predict. At Ad Leverage, we treat that as the kind of short, forecastable event the feature is built for. We don’t assume Smart Bidding can see the forecast for your metro, and we don’t claim it can’t. We plan as if it learns about the spike only once conversions start landing.
The trade press already points in this direction. ACHR News recommends using adjustments when “a massive heatwave is coming next week.” We agree with the instinct, but it leaves out three limits: eligibility, sizing the change accurately, and whether you can actually run the extra jobs.
Pro tip: Build the adjustment once the forecast firms up a few days out, not a week early on a hunch. A tight start and end time beats a long, hopeful window every time.
Eligibility: which campaigns can actually use it
According to Google’s “About seasonality adjustments” page, Search, Shopping, Demand Gen and Display campaigns are eligible only when they use Target CPA or Target ROAS. Performance Max is eligible on all bid strategies, App campaigns are in beta, and Travel campaigns aren’t supported.
| Campaign type | Eligible bid strategies | What it means for a typical HVAC account |
|---|---|---|
| Search | Target CPA or Target ROAS | Your core emergency and repair campaigns qualify only if they run on a target |
| Performance Max | Any bid strategy | Eligible regardless of setup, so PMax may be the easiest place to apply it |
| Display | Target CPA or Target ROAS | Rarely a cold snap priority for lead gen |
| Demand Gen | Target CPA or Target ROAS | Listed on one Google page but missing from another, so confirm in your account |
| Shopping | Target CPA or Target ROAS | Not relevant for most service businesses |
One detail worth knowing: Google’s “Create a seasonality adjustment” page leaves Demand Gen off its eligibility list, while the “About” page includes it. We go by the “About” page, but check the campaign selection list before relying on it.
Campaigns running without a bidding target
Many HVAC Search campaigns run Maximize Conversions or Maximize Clicks with no target set. Based on Google’s eligibility list, those campaigns probably can’t use a seasonality adjustment, but this is something to confirm in your own account rather than assume.
The simplest check is to start building an adjustment and see whether the campaign appears as selectable. If you’ve set an optional target CPA inside Maximize Conversions, confirm in the interface whether that makes it eligible.
Don’t switch bid strategies the week before a freeze just to qualify. A bid strategy change right before your busiest stretch adds its own volatility. If you want the option next season, settle the bid strategy during a quiet month. Our guide on how to structure Google Ads for service businesses that need real leads covers how to set that foundation.
Cold snap decision table: four situations, four tools
Most cold snap advice blends three different problems into one “spend more” instruction. Decide which problem you actually have, then pick the tool built for it.
| Situation | What it looks like | Right tool | Why |
|---|---|---|---|
| Campaign is limited by budget | “Limited by budget” status, impression share lost to budget, ads stop showing mid-day | Seasonal budget adjustment | Schedules a temporary increase to the average daily budget for an event Google wouldn’t otherwise be aware of |
| Conversion rate is expected to jump | Firm freeze forecast, open slots on the board, conversions tied to real booked jobs | Seasonality adjustment | Tells Smart Bidding to expect a higher conversion rate for a short window |
| Tracking broke | Call tracking outage, form stopped firing, duplicate conversions recorded | Data exclusion | Keeps bad conversion data out of what Smart Bidding learns from |
| Schedule is already full | Dispatch booked out through the forecast window | No change | More leads you can’t serve raise cost per booked job and hurt the customer experience |
Google’s documentation on seasonal budget adjustments describes them as a way to schedule a temporary budget increase for a limited-time event that “unlike market seasonality, Google wouldn’t be aware of.” They live in the same Adjustments area as seasonality adjustments, and you pick “Budget” as the type. Consecutive budget adjustments are allowed.
The two can work together. If a campaign is budget-limited and you also expect a real conversion rate jump, a budget adjustment gives Smart Bidding room to act on the seasonality adjustment. A seasonality adjustment on a budget-capped campaign just competes for the same fixed dollars.
Why flat percentage rules miss the point
You’ll see advice to raise bids or budgets by a set percentage whenever temperatures drop. In a Smart Bidding campaign, there’s no manual keyword bid to raise, and a blanket budget increase doesn’t help a campaign that wasn’t spending its budget to begin with.
The flat rule also ignores your actual numbers. A shop with three idle techs and a shop with a two-day backlog should not respond to the same forecast the same way.
When to hold back
No ranking advice we found tells operators to sit out a cold snap, but it’s often the right call. If dispatch is booked out, extra paid clicks turn into callbacks next week, unbooked leads, or customers who call a competitor anyway.
Run this capacity check before touching any adjustment:
- Open slots in the window. Count unbooked appointment slots for the exact forecast dates, not the week overall.
- Tech availability. Confirm who is scheduled, who is on call, and whether overtime is realistic.
- Call handling. Make sure the CSR team or after-hours answering can absorb a spike without letting calls ring out.
- Parts and equipment. Check stock on common no-heat repair parts so booked calls turn into completed jobs.
- Membership commitments. Leave room for maintenance agreement customers who expect priority service.
If most of those come back tight, leave the campaigns alone. The cheapest lead is the one you didn’t buy for a slot you didn’t have.
How to size and set up a cold snap adjustment
Compare your conversion rate during last year’s first cold snap with the weeks just before it, turn the difference into a percentage, trim it for uncertainty, and apply it for 1 to 7 days on eligible campaigns only.
- Confirm capacity. Run the checklist above. If the board is full, stop here.
- Confirm eligibility. List the campaigns on Target CPA, Target ROAS or Performance Max. Everything else is out of scope for this tool.
- Confirm what you’re optimizing toward. The adjustment applies to the conversion action Smart Bidding uses. If that’s raw calls, a spike in wrong numbers and price shoppers can look like success. Booked-job conversions imported from your CRM give a far cleaner signal, which is why better tracking matters more than more Google Ads spend.
- Pull last year’s numbers. Find the first real cold snap dates from last season. Compare the conversion rate (conversions divided by clicks) during those days with the baseline from the two to four weeks before.
- Calculate and trim. Divide the event rate by the baseline rate and subtract one to get the percentage change. Then trim it, because this year’s freeze may be milder, shorter, or hit on a weekend.
- Build the adjustment. In the Adjustments area under Tools, create a seasonality adjustment, set the start and end time to match the forecast window, choose campaigns or campaign types, and enter the percentage. You can also limit it to certain device types.
- Review afterward. Compare cost per booked job for the window against baseline, and note what you’d change next time.
Worked example (illustrative numbers)
The numbers below are hypothetical, to show the math. Say a single-market HVAC company imports booked jobs as its primary conversion. In the three weeks before last year’s first freeze, its Search campaigns converted 8% of clicks into booked jobs. During the three-day freeze, that rose to 12%.
The change is 12 divided by 8, minus one, which is a 50% lift. This year’s forecast looks a little shorter, and the company only has open slots for about two and a half days, so the marketing manager sets +35% for three days on the Target CPA Search campaigns and the PMax campaign.
When the window closes, bids return to normal on their own. Per Google, there’s no need to add a negative adjustment afterward.
If you have no clean history from last year, don’t guess high. A smaller adjustment that undershoots costs you a few jobs. An oversized one teaches you an expensive lesson in CPC inflation.
Pro tip: Judge the window on cost per booked job, not cost per lead. Lead volume almost always rises in a freeze. The question is whether those leads became revenue, which is why cost per lead doesn’t tell the whole story.
Multi-location brands: setting it up from a manager account
Google allows you to create a seasonality adjustment in a manager account (MCC) and apply it to linked client accounts. Accounts linked after the adjustment is created don’t inherit it, so a newly acquired location needs its own setup.
A single event can include up to 2,000 campaigns, or you can select by campaign type instead of picking campaigns one by one.
The adjustment is scoped by campaign and device type, not by location. If a cold front hits your northern markets and spares the southern ones, the only way to aim it is through campaign structure: separate campaigns or accounts per metro. That’s one more reason market-level splits pay off, and it ties into how to allocate budget across Google Ads, LSAs and Performance Max without guessing.
Brands that want to automate adjustments from weather triggers can create them through the Google Ads API using the BiddingSeasonalityAdjustment resource. Google’s API docs note that the CUSTOMER scope is read-only and can’t be used to create adjustments, so plan to target campaigns or channel types instead.
Frequently asked questions
Do seasonality adjustments work if my campaign has no bidding target?
Google’s eligibility list for Search, Shopping, Demand Gen and Display names only Target CPA and Target ROAS, so a Maximize Conversions campaign with no target probably isn’t eligible. Performance Max is the exception, since it qualifies on any bid strategy. Check by starting an adjustment and seeing whether your campaign appears in the selection list.
How long can a seasonality adjustment run?
Google says adjustments work best for events of 1 to 7 days and may not work as well past 14 days. For a cold snap, match the window to the forecast and your open capacity. Longer stretches are better left to Smart Bidding’s normal learning.
Do I need a negative adjustment after the event?
No. Google states that bids return to normal once the adjustment ends, and you don’t need to add a negative adjustment to offset it. Adding one could push bids too low right as demand settles.
Should I use a seasonality adjustment for the whole heating season?
No. Google warns that Smart Bidding already manages seasonal events and recommends the feature only for major, short-lived conversion rate changes. The gradual move into heating season is the kind of trend the system picks up on its own.
Can I target only the metro area getting the cold front?
Not directly. Adjustments are scoped by campaign or device type, not location. To aim one at a single metro, that metro needs its own campaigns or account, so the adjustment can be applied to them alone.
How is a seasonality adjustment different from a regular bid adjustment?
A regular bid adjustment changes bids for a segment like device, location or schedule on an ongoing basis. A seasonality adjustment tells Smart Bidding to expect a different conversion rate for a fixed window, and the bidding system decides what to bid from there. It ends automatically when the window closes.
How Ad Leverage handles cold snap bidding
We start with the dispatch board, not the forecast. Before any adjustment goes live, we check open capacity for the window, confirm which campaigns are eligible, and confirm that the conversion Smart Bidding sees reflects booked jobs rather than raw calls.
As a ServiceTitan partner, we size adjustments from each client’s own booked-job history wherever that data is connected, then review cost per booked job after every event so the next freeze gets a better-calibrated number. For multi-location brands, we set up campaign structure ahead of the season so a regional cold front can be targeted to the markets it actually hits.
If you want a second set of eyes on whether your account is ready for this winter’s first freeze, our Google Ads team can walk through eligibility, tracking and capacity with you.
