Google Ads Seasonality Adjustments: How to Prepare Your Campaigns for Peaks and Dips
Seasonality can have a huge impact on the performance of your Google Ads campaigns. Whether you’re preparing for a surge in demand during Black Friday or anticipating a slowdown after Christmas, failing to account for these fluctuations can lead to wasted ad spend and poor campaign performance.
Fortunately, Google Ads includes a feature called Seasonality Adjustments, designed to help advertisers guide Smart Bidding during predictable changes in conversion behaviour.
In this guide, we’ll explain what Google Ads seasonality adjustments are, why they matter, and exactly how to set them up correctly.
What Are Google Ads Seasonality Adjustments?
Seasonality adjustments are advanced controls within Google Ads that allow you to temporarily inform Google’s Smart Bidding system about expected changes in conversion rates or campaign demand.
These adjustments are especially useful during short-term events such as:
- Black Friday
- Cyber Monday
- Christmas sales
- Boxing Day promotions
- Limited-time offers
- Product launches
- Seasonal slow periods
Instead of allowing Google to react blindly to sudden market changes, seasonality adjustments give the platform guidance on what you expect to happen.
Why Seasonality Adjustments Matter
Google’s automated bidding systems are designed to optimise performance based on historical data and real-time signals. However, they do not always understand the unique seasonal trends of your business.
For example:
- You may know demand will spike dramatically during a major promotion.
- You may expect conversions to fall significantly during holiday downtime.
- You may need temporary budget increases to capitalise on extra demand.
Without adjustments, Google may continue spending aggressively during weak periods or fail to scale quickly enough during high-demand events.
The Risk of Ignoring Seasonality
One of the biggest dangers of ignoring seasonality is that Google will continue attempting to spend your allocated budget regardless of market demand.
During low-demand periods, this can lead to:
- Increased CPCs (cost-per-click)
- Lower conversion rates
- Wasted ad spend
- Poor return on ad spend (ROAS)
As explained in the transcript, Google’s systems will often keep increasing bids in an attempt to spend the full budget, even when fewer users are searching or converting.
This is why seasonality adjustments can become an important safeguard for advertisers.
Positive vs Negative Seasonal Trends
Seasonality adjustments can be used in two main ways:
Positive Seasonal Trends
A positive trend occurs when you expect demand and conversions to increase.
Examples include:
- Black Friday
- Christmas shopping periods
- Flash sales
- Major promotional events
In these situations, you may want Google Ads to:
- Increase spend temporarily
- Bid more aggressively
- Capture additional traffic and conversions
For instance, if you know Black Friday will bring a major spike in searches, you can temporarily raise campaign budgets to ensure your ads remain competitive.
Negative Seasonal Trends
A negative trend happens when you expect conversion rates to decline.
Examples include:
- The period between Christmas and New Year
- Industry downtime
- Seasonal closures
- Low-demand periods
In these situations, you can tell Google to expect lower conversion rates, helping prevent excessive bidding and overspending.
Why Simply Changing Budgets Is Not Enough
Many advertisers attempt to manage seasonality by manually increasing or decreasing campaign budgets.
However, this can create problems because Google evaluates budgets over a rolling 30-day period.
For example:
- You increase your budget significantly during Black Friday week.
- You later reduce it back to normal.
- Google still interprets the campaign as having a higher average budget over the 30-day window.
This can result in unexpected overspending after the promotional period ends.
Seasonality adjustments provide a more controlled and temporary solution.
Types of Google Ads Seasonality Adjustments
Google Ads offers two primary adjustment types:
1. Temporary Budget Adjustments
This allows you to temporarily increase or modify campaign budgets during a defined period.
For example:
- Increase your daily budget during Black Friday weekend
- Add extra spend capacity during a major sale
- Prepare for expected spikes in search volume
The adjustment only applies during the selected timeframe.
2. Conversion Rate Adjustments
This option allows you to tell Google Ads that conversion rates are expected to rise or fall temporarily.
You can specify:
- An expected increase in conversions
- An expected decrease in conversions
- Device-specific changes
- Campaign-specific adjustments
This helps Smart Bidding react more appropriately during unusual periods.
How to Set Up Google Ads Seasonality Adjustments
Now let’s walk through the process step by step.
Step 1: Open Bid Strategies
Inside Google Ads:
- Click Tools and Settings
- Navigate to Bid Strategies
- Select Advanced Controls
This section contains the seasonality adjustment settings.
Step 2: Create a New Adjustment
Click the blue plus (+) button.
You will then choose between:
- Temporary Budget Adjustment
- Conversion Rate Adjustment
Step 3: Name Your Adjustment
Google Ads requires every adjustment to have a name.
It’s recommended to use clear naming conventions such as:
- Black Friday 2026 Budget Boost
- Christmas Conversion Decline
- Summer Sale Adjustment
You can also add an optional description for future reference.
Step 4: Set Start and End Dates
Choose:
- Start date
- End date
- Start time
- End time
Adjustments can run:
- Across full days
- During specific hours
- For short promotional windows
For example:
- 1st December to 10th December
- Midnight to midnight
- Black Friday weekend only
Step 5: Choose Campaigns
You can apply adjustments to:
- Individual campaigns
- Multiple campaigns
- Entire campaign types
Examples include:
- Search campaigns only
- Performance Max campaigns
- Specific promotional campaigns
Step 6: Configure the Adjustment
For Budget Adjustments
You will see:
- Current daily budget
- New temporary budget amount
For example:
- Existing budget: £100/day
- Temporary uplift: +£200/day
- Total temporary budget: £300/day
This gives Google more spending flexibility during periods of increased demand.
For Conversion Rate Adjustments
You can specify:
- Increase or decrease
- Percentage change expected
For example:
- Expected conversion decrease: 20%
- Timeframe: Christmas to New Year
This helps Smart Bidding reduce bidding aggressiveness during weaker periods.
Device-Level Adjustments
One advanced feature is the ability to make device-specific seasonality adjustments.
For example:
- Mobile conversion rates may fall after a website update
- Desktop users may convert better during a promotional event
You can use these settings to guide Google’s bidding by device type.
Important Warnings About Smart Bidding
Although Google suggests Smart Bidding can automatically adapt to seasonal changes, the transcript warns against relying entirely on automation.
According to the video:
- Google may continue trying to spend aggressively during low-demand periods
- CPCs can rise unnecessarily
- Budgets may be exhausted inefficiently
This is why manual seasonality guidance can still be extremely valuable, especially during major fluctuations.
Best Practices for Seasonality Adjustments
To get the best results:
Use Adjustments for Short-Term Events
Seasonality adjustments work best for temporary changes, not permanent business trends.
Good examples include:
- Weekend sales
- Holiday spikes
- Flash promotions
Avoid Overusing Them
Do not constantly adjust campaigns for minor fluctuations.
Google’s Smart Bidding still performs well under normal market conditions.
Monitor Performance Closely
After applying adjustments:
- Watch CPCs
- Review conversion rates
- Check impression share
- Monitor ROAS
This helps ensure the adjustment is working as intended.
Plan Ahead
Don’t wait until the event has already started.
Set adjustments in advance so Google’s systems can prepare accordingly.
Final Thoughts
Google Ads seasonality adjustments are one of the most underused but powerful tools available to advertisers using automated bidding strategies.
By proactively informing Google about expected changes in demand or conversion behaviour, you can:
- Protect your ad spend during slow periods
- Maximise visibility during high-demand events
- Prevent excessive CPC inflation
- Improve overall campaign efficiency
Whether you’re preparing for Black Friday, a major sale, or a seasonal slowdown, properly configured seasonality adjustments can help your campaigns remain profitable and controlled throughout the year.
