What are seasonality adjustments in Google Ads?

Seasonality adjustments let you tell Smart Bidding to expect a change in conversion rates during a future event, such as a sale or promotion. Bids adjust during the event and return to normal afterward. Google designed them for short events of one to seven days.

Are seasonality adjustments a good idea for holidays?

For widely known holidays and seasons, the evidence favors leaving them off. Google says Smart Bidding already manages seasonal events, and an Optmyzr analysis published by Search Engine Land found higher CPCs and lower ROAS for advertisers who used adjustments over Black Friday. Adjust budgets or targets instead.

What is the difference between seasonality adjustments and data exclusions?

Seasonality adjustments forecast a real change in conversion rates. Data exclusions tell Smart Bidding to set aside conversion data distorted by problems such as broken tags, site outages or failed uploads.

Can I apply seasonality adjustments to multiple accounts?

Yes. Google lets you create them from a manager account and apply them to a campaign type across linked client accounts or to specific campaigns. Accounts linked after you apply one need their own adjustment.

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Google Ads Seasonality Adjustments: When to Use Them for Lead Gen

Seasonality adjustments suit short events you create, such as an open house or an email push. For predictable seasons, plan budgets and targets instead.

Oct 20, 2026 · 5 min read

Google Ads seasonality adjustments shown as a rooftop weather vane swinging toward a short change in the weather.

The short answer

Google Ads seasonality adjustments tell Smart Bidding to expect a short, sharp change in conversion rates during a future event. Google designed them for events of one to seven days that bidding has yet to see in your data, such as your own promotion or a large email push. For predictable seasons like back-to-school, January or year-end, Smart Bidding already learns the pattern, so budgets and targets do that work better.

Use adjustments for surprises you create. Let bidding handle the calendar.

Start with what bidding already knows

Smart Bidding learns from your account history and from real-time auction signals. Google's help page says to use seasonality adjustments only when you expect major changes to conversion rates, because Smart Bidding already manages seasonal events.

For example, many lead generation brands see busy periods that repeat every year:

Childcare enrollment ahead of fall and January starts
Dental demand as insurance benefits reset early in the year or run toward year-end
New-year health goals for clinics and wellness practices
Summer heat and winter freezes for home services

Those peaks live in your history, and bidding reads them. Your job is to fund them well. That means budgets that can carry the peak, landing pages that reflect seasonal offers and conversion tracking that stays clean through the busy weeks.

What the data says about adjustments on predictable peaks

Search Engine Land published an Optmyzr analysis of advertisers during Black Friday and Cyber Monday. In 2024, across 5,886 accounts, advertisers who used seasonality adjustments saw CPCs rise 34%, twice the 17% increase for advertisers who left Smart Bidding alone. ROAS fell 15.7% for the adjusters and rose 5.7% for the rest, and Optmyzr says the pattern held in 2022 and 2023.

Optmyzr notes that it compared two groups of advertisers rather than running a controlled experiment, and the study covers retail. The lesson still carries over to lead generation: an adjustment on a peak Google already expects counts the lift twice, and an overestimate raises bids across every auction at the most expensive time of year.

When a seasonality adjustment fits

Optmyzr lists the events adjustments are built for, the ones outside Google's view. They translate well to local lead generation:

Your own short promotion, such as a new-patient special weekend
A one-off event, such as an enrollment open house across all centers
A large email or SMS push to past patients, families or customers
A niche local event with little broad history, such as a community health fair

7 rules for Google Ads seasonality adjustments in lead generation

1. Keep the window short

Google says adjustments are ideal for events of one to seven days and may work less well beyond 14 days at a time. For a month-long enrollment season, plan budgets and targets instead. Shorter events also make results easier to read.

2. Estimate the change from your own history

An adjustment asks you to predict the conversion rate change. Base it on past events of the same type, by location where possible. For example, if last spring's open house weekend converted at 1.3 times the normal rate, a 30% increase is a defensible starting point, while a guess of 100% invites overbidding.

3. Match the scope to the event

Scope the adjustment to the campaigns serving the locations that run the event, and leave the rest of the network on normal bidding. Groups that manage several accounts can create adjustments from a manager account and apply them across linked accounts or to specific campaigns.

4. Check the bid strategy first

Google lists seasonality adjustments for Search, Shopping, Demand Gen and Display campaigns using Target CPA or Target ROAS, plus Performance Max campaigns with any bid strategy. Confirm each campaign's strategy before you schedule one.

5. Change the target when you want more volume

Optmyzr's point applies directly: if the business wants more leads during a peak and accepts a higher cost per lead, raise the target CPA and say so plainly. A target change states what you will pay. An adjustment is a forecast. Lowering a Target ROAS does the same job for accounts that bid on lead value.

6. Use data exclusions for tracking outages

Seasonality adjustments are for real changes in demand. When a broken tag, a site outage or a failed CRM upload distorts conversion data, Google recommends data exclusions instead. Exclude the affected clicks, allow for your usual conversion delay, and leave the exclusion in place once applied.

7. Set guardrails before the event

Set CPC and spend pacing alerts before the event starts, confirm the budget can carry the extra demand, check pacing by location as well as by account, since one busy center can absorb a shared budget, and review results the morning after each event day. Record each adjustment and its outcome, so next year's estimate starts from evidence.

Decreases count too

Seasonality adjustments can lower expected conversion rates as well as raise them. Google describes them as scheduling a conversion rate change, an increase or a decrease, for an upcoming event. For example, if online booking will be offline for a planned half-day system update while calls continue, the real conversion rate on form-driven campaigns falls for those hours, and a short decrease keeps bids in line.

Keep the distinction clear. A real change in how many people convert calls for a seasonality adjustment. A change in how many conversions you can measure, such as a broken tag, calls for a data exclusion.

Common mistakes to avoid

Adding an adjustment to a holiday or season Smart Bidding has seen many times before
Running one adjustment across an entire month-long season
Setting the increase from hope instead of last year's results
Applying an account-wide adjustment for an event at a handful of locations
Leaving an adjustment in place after the event dates change
Using an adjustment to fix a tracking outage

A seasonal planning calendar for lead generation

01Eight weeks out: list every planned promotion, open house and email push by location.
02Six weeks out: pull conversion rates from last year's similar events.
03Four weeks out: set budgets for the predictable season and agree on targets.
04One week out: schedule seasonality adjustments for short, self-created events only.
05During the event: watch CPC, pacing and lead quality daily.
06After the event: compare the actual conversion rate with your estimate and log the result.

How SalesX plans for peak days

SalesX plans peak demand around budget pacing and targets set from lead value, and keeps seasonality adjustments for the short events a client creates.

SalesX's published Aeroflow case study reports that X-Octane acceleration of peak performance days produced a 43% year-over-year increase in conversions. These are historical, client-specific outcomes, shared as context.

Want a senior strategist to pressure-test your account? Request a free X-Audit. It is built for U.S. advertisers spending $50k+ per month, and the analysis typically takes three to five working days after access is approved.

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The bottom line

Seasonality adjustments are a precise tool for short events you create. For the seasons everyone sees coming, trust Smart Bidding, plan budgets early and change targets openly. Keep a log of every event, and each year's plan gets sharper.

Sources and further reading

FAQ

What are seasonality adjustments in Google Ads?: Seasonality adjustments let you tell Smart Bidding to expect a change in conversion rates during a future event, such as a sale or promotion. Bids adjust during the event and return to normal afterward. Google designed them for short events of one to seven days.
Are seasonality adjustments a good idea for holidays?: For widely known holidays and seasons, the evidence favors leaving them off. Google says Smart Bidding already manages seasonal events, and an Optmyzr analysis published by Search Engine Land found higher CPCs and lower ROAS for advertisers who used adjustments over Black Friday. Adjust budgets or targets instead.
How long can a seasonality adjustment run?: Google says adjustments are ideal for one to seven days and may work less well beyond 14 days at a time. For a longer season, plan budgets and targets.
What is the difference between seasonality adjustments and data exclusions?: Seasonality adjustments forecast a real change in conversion rates. Data exclusions tell Smart Bidding to set aside conversion data distorted by problems such as broken tags, site outages or failed uploads.
Can I apply seasonality adjustments to multiple accounts?: Yes. Google lets you create them from a manager account and apply them to a campaign type across linked client accounts or to specific campaigns. Accounts linked after you apply one need their own adjustment.

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