Google Ads seasonality adjustments for Black Friday

A seasonality adjustment tells Smart Bidding to expect a short, temporary jump in conversion rate, so it bids for that jump from the first hour instead of learning it halfway through the sale. Use one for the core Black Friday to Cyber Monday window (November 27 to 30, 2026), keep it under 7 days, and base the percentage on your own conversion rate from last year's sale. Google says adjustments are "ideal for short events of 1–7 days" and should be used "only if you expect major changes to conversion rates" (Google Ads Help).

This guide is for advertisers already running Smart Bidding on Shopping, Performance Max or Search. For the full Black Friday preparation, from reference prices to promotions, start with our Black Friday Google Ads checklist.

What does a seasonality adjustment actually change?

It changes one input: the conversion rate Smart Bidding expects during a date range you set. Smart Bidding normally predicts conversion rates from recent history, and it adapts to a sudden change only after it has seen enough conversions, which a 4-day sale barely leaves time for. An adjustment hands it the expected change in advance. Google's example: if you expect conversion rates to rise by 50% during a 3-day sale, you can add up to a +50% adjustment for those 3 days (create a seasonality adjustment).

What it does not change: your budgets, your targets or your ads. When the event ends, campaigns return to their usual behavior, and Google states that "no negative adjustment is needed when the promotion is over".

Which campaigns and bid strategies support seasonality adjustments?

Source: About seasonality adjustments, as of October 2026. Standard Shopping on Maximize clicks or manual CPC is out of scope, since there is no conversion model to adjust.

When should you use one for Black Friday, and when not?

Seasonality adjustments are common practice, though not universal: in an informal LinkedIn poll of 169 advertisers reported by PPC Land in 2024, 65% said they use them for Black Friday.

How do you estimate the right percentage?

From your own account, not from a benchmark. Your discount depth, catalog and audience decide the lift, and an adjustment that overshoots makes Smart Bidding bid too high for the whole window.

1. Pull last year's conversion rate for the sale window (Black Friday to Cyber Monday 2025) for the campaigns you will adjust. Use conversions divided by clicks, by campaign or by campaign type.
2. Pull a baseline: the same campaigns over the 14 days before last year's sale started.
3. Divide and subtract one. If the sale converted at 3.6% against a 2.4% baseline, the lift was 3.6 / 2.4 − 1 = 50%.
4. Adjust for this year's offer. A smaller discount than last year means a smaller lift. If in doubt, set the adjustment below your estimate: Google's wording is "add up to" the expected change.
5. Split by campaign when lifts differ. Brand Search, prospecting Performance Max and promoted-product Shopping rarely move by the same amount; create one adjustment per group.

No history from last year, or a different offer? Use the first few hours of the sale instead: compare the conversion rate so far with the baseline and create the adjustment for the remaining days. It still beats letting Smart Bidding catch up on its own over a 4-day window.

How do you set up a seasonality adjustment in Google Ads?

The steps below follow Google's help page on creating a seasonality adjustment (as of October 2026):

1. Click Tools, open Budgets and bidding, then Adjustments.
2. Select Seasonal at the top, then the blue plus button.
3. Under Adjustment type, select Conversion rate.
4. Name it clearly, for example "BFCM 2026 – PMax promoted – +40%", and set the start and end dates.
5. Choose the scope: all campaign types, specific campaign types or specific campaigns.
6. Enter the conversion rate adjustment, then click Save and Create seasonality adjustment.

Agencies can create the adjustment from a manager account and apply it to all linked accounts, specific accounts or specific campaigns, up to 2,000 campaigns per event. Client accounts linked after the adjustment is created don't inherit it, so add them separately.

A suggested setup for 2026, with Black Friday on Friday, November 27 and Cyber Monday on November 30 (Universal Time Date):

Both stay under 7 days. Create them now, then edit the percentages once your offer is final.

How does it work with Performance Max?

Performance Max accepts seasonality adjustments with every bid strategy, so it is the easiest place to apply one. Two points to watch:

• Budget first. An adjustment raises bids, not budgets. If a campaign is already limited by budget, higher bids spend the budget faster without buying more volume. Google can spend up to twice your average daily budget on a given day, but no more than 30.4 times it over a month (Google Ads Help), so raise budgets on promoted campaigns before the weekend.
• Channel mix. Higher bids apply across every channel Performance Max serves, not only Shopping. Check where the extra spend goes during the event; our guide to the Performance Max spend report by asset group shows how, and spend leaking to the wrong channel is one of the common Performance Max mistakes.

Clarmix PMax Insights tracks conversion volume health, spend outside Shopping (YouTube, Search, Display) and branded search terms in each Performance Max campaign, with alerts, which helps spot a shift while the adjustment is running.

Should you change target ROAS at the same time?

Not during the event. A seasonality adjustment and a new target both move bids, and stacking them makes it impossible to tell which one caused what. Set target ROAS for the season beforehand, as covered in our guide on updating target ROAS after Google's August 2026 bidding update, then let the adjustment handle the sale days.

What if conversion tracking breaks during Black Friday?

Use a data exclusion, not a seasonality adjustment. Data exclusions tell Smart Bidding to ignore conversion data from a period with a tracking or upload problem, such as a broken tag after a checkout change. They work on Search, Display, Shopping and Performance Max with conversion-based Smart Bidding, they only affect the data Smart Bidding uses (not your reports), and Google advises against using them "frequently or for prolonged periods" (About data exclusions). Pick a date range that covers the outage plus your typical conversion delay.

Common mistakes with seasonality adjustments

• One long adjustment for the whole of November. Split it, or skip it.
• Copying someone else's percentage. The lift depends on your discount and catalog.
• Adding a negative adjustment after the sale. Not needed, according to Google.
• Adjusting a budget-limited campaign. Raise the budget first.
• Forgetting new client accounts. Accounts linked to a manager after the adjustment was created are not covered.

Frequently asked questions

Do seasonality adjustments work with Maximize conversion value?

On Performance Max, yes: it supports every bid strategy. On Search, Shopping, Demand Gen and Display, Google lists target ROAS and target CPA as the supported strategies.

How far ahead should I create the adjustment?

Google doesn't set a minimum lead time. Creating it a few days ahead lets you check the scope and dates calmly; you can still edit the percentage until the event starts.

Can I use a seasonality adjustment for Cyber Monday only?

Yes. A one-day event is within the 1 to 7 days Google recommends. Set it for the specific campaigns where you expect the lift.

What happens to bids after the adjustment ends?

Campaigns return to their pre-event behavior on their own. Google says no negative adjustment is needed afterward.

Sources

• About seasonality adjustments (Google Ads Help)
• Create a seasonality adjustment (Google Ads Help)
• About data exclusions (Google Ads Help)
• About overdelivery and your average daily budget (Google Ads Help)
• When is Black Friday 2026? (Universal Time Date)
• 65% of advertisers use Google Ads seasonality adjustments for Black Friday sales (PPC Land)

Cover photo by Towfiqu barbhuiya on Unsplash.