Iowa 7-Day Forecast: Heat Wave Ahead — Highs 89°F to 96°F Through July 7
Today (Tue, June 30): High 96°F
Independence Day (July 4): High 93°F
What changed
The NWS forecast for central Iowa (Des Moines area) shows a sustained run of high temperatures:
- Today (Tue, June 30): High 96°F
- Tonight: Low 75°F
- Wednesday (July 1): High 94°F
- Wednesday Night: Low 75°F
- Thursday (July 2): High 93°F
- Thursday Night: Low 73°F
- Friday (July 3): High 93°F
- Friday Night: Low 72°F
- Independence Day (July 4): High 93°F
- Saturday Night: Low 70°F
- Sunday (July 5): High 89°F
- Sunday Night: Low 68°F
- Monday (July 6): High 89°F
- Monday Night: Low 68°F
The hottest day is today at 96°F. From Wednesday through the Fourth, highs hold at 93–94°F. The weekend brings a modest step-down to 89°F. Overnight lows range from 68°F to 75°F — the warmest nights come early in the week.
Why it matters
Early July is when a large share of Iowa corn enters or approaches pollination. Sustained daytime highs in the 90s, combined with overnight lows in the 70s, mean the crop gets limited relief from heat stress overnight. That combination could affect pollen viability and silk receptivity if it persists.
For soybeans moving into early bloom, extended heat may influence flower retention. The degree of impact depends heavily on soil moisture — fields with adequate moisture handle heat better than those already running dry.
This is a weather pattern worth watching, not a crisis call. Local conditions vary, and a few degrees or a timely rain can change the picture.
What to watch next
- Updated NWS forecasts later this week — check whether the 89°F weekend outlook holds or shifts back hotter.
- Overnight lows — if those stay above 70°F through the week, cumulative heat stress adds up faster.
- Rainfall chances — the forecast facts here cover temperature only. Any rain in the mix could offset heat stress significantly.
- Your own fields — crop stage varies farm to farm. Knowing where your corn is relative to tassel and silk matters for reading this forecast.
Source notes
All temperatures from the U.S. National Weather Service API, Des Moines (DMX) grid forecast. Data accessed June 30, 2026.
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