Summer CPM Seasonality and Planning the H2 UA Budget

CPMs soften every summer, reliably enough that treating it as a surprise each July is itself a planning failure. The mid-year dip is not a market anomaly; it is a demand-side pattern driven by advertiser budget cycles, by seasonal shifts in consumer attention and by a lighter release calendar across most of the categories that compete with mobile games for the same inventory. Whether summer CPM seasonality happens is not the operator question. The question is whether a team built its H2 budget to take advantage of it.

Why summer CPM seasonality happens

Several forces compound in the same direction through July and August. Many advertisers, across categories well beyond mobile games, pull back spend around the northern hemisphere summer as internal budget cycles slow and fewer big campaigns launch. Consumer attention itself shifts outdoors and toward travel in several key markets, which some networks report as softer engagement on certain ad formats even as raw impression volume holds up. And the release calendar across games and other app categories usually runs lighter through summer than it does in spring or the run-up to the holidays, which leaves less competitive pressure bidding up the same inventory.

None of these forces is new information to an experienced buyer. What is worth resisting is the instinct to read a lower CPM in July as evidence that a campaign is suddenly performing better, rather than as evidence that inventory is simply cheaper for reasons that have nothing to do with creative quality or audience fit.

The two effects look identical on a CPI dashboard and require different responses.

Building flexibility into the H2 budget

Spending more in summer purely because it is cheaper risks buying volume the team cannot productively use. The real opportunity is an H2 budget shape with enough give in it that a team can lean into the summer dip where it is genuinely accretive, then redeploy that same flexibility when CPMs rise again heading into the autumn release wave and holiday season.

A workable structure allocates a base spend level across July and August that the team is confident it can sustain without diluting creative testing quality, plus a flexible tranche, held separately, that only deploys when CPMs actually soften below a pre-agreed threshold rather than on a fixed calendar date. Set that threshold against the team's own historical CPM data by channel, never a generic industry benchmark. How deep the dip goes and when it lands varies by genre as much as by platform or region.

A worked example

Take a hypothetical mid-size puzzle publisher with a $2M quarterly UA budget. A rigid quarterly-even split would allocate roughly $667,000 per month regardless of market conditions. A seasonality-aware plan instead sets a $500,000 base for each of July and August, with a $334,000 flexible tranche held back and released only once blended CPM on the team's core channels drops more than 12% below its Q2 average. If that threshold triggers in the third week of July, the team deploys the tranche over the remaining five weeks of the summer window, buying additional volume at genuinely favourable rates rather than spreading it thin across a period when CPMs may not have actually softened yet.

Run that same flexible-tranche logic in reverse heading into September, when CPMs typically firm up again as advertisers return from the summer lull and the autumn release calendar fills back in. A team that spends its full flexible allocation on the assumption that summer softness will persist finds itself under-resourced exactly when competitive pressure returns, because the plan never accounted for the reversal.

Creative supply needs to keep pace with the flexible tranche

A flexible spend tranche is worth nothing without creative ready to absorb it the moment CPMs soften. This is where seasonality planning most often falls over. A team that builds the budget flexibility described above without a matching flexible creative supply ends up delaying the extra spend until new concepts are ready and missing the cheapest window of the dip, or else pushing existing creative harder into the additional volume, which accelerates fatigue on assets already carrying a normal spend load.

The fix: treat creative production the same way as the spend tranche. Hold a small reserve of tested-but-not-yet-scaled concepts earmarked for a summer CPM window, rather than assuming the standard production cadence will happen to have fresh material ready exactly when the threshold triggers. Coordinate the creative and media-buying sides of this plan before July, not once the dip is already underway. That is what lets a team capture the cheaper inventory instead of watching the window close while new assets sit in review.

A checklist for the transition

• Pull two to three years of your own CPM data by channel for July and August, rather than relying on generic seasonality claims, since the size and timing of the dip is platform and region specific.
• Set a base spend level for summer that the team can sustain without compromising testing quality, separate from any opportunistic flexible tranche.
• Trigger the flexible tranche on an actual CPM threshold against your own historical baseline, not a fixed calendar date, so the plan responds to real market conditions rather than an assumption about when summer softness will land.
• Plan the reversal in the same document as the opportunity: know in advance how much of the flexible tranche you expect back in reserve heading into September, rather than treating the summer spend plan and the autumn one as separate exercises.
• Review actual CPM movement against the plan weekly through July and August, since the dip's depth and duration shift year to year even where the general pattern holds. This kind of scenario-based flexibility is the same principle we set out in Building a UA vendor diversification plan early, applied to timing rather than to channel mix.

Summer CPM softness is one of the more predictable patterns in the UA calendar, which makes it one of the cheaper ones to plan around properly.

The teams that treat it as an annual surprise spend the same money less efficiently than the teams that built the flexibility to use it in advance.

Related archive reading

These articles provide related context and remain subject to their stated review status.

• GTA 6's autumn campaign will distort mobile CPMs. Plan for it now
• GTA 6 preview: viewership jumped 35%, plan CPMs