Iowa 7-Day Forecast: Highs Jump From 68°F to Mid-80s by Memorial Day Week

What changed

The National Weather Service forecast for central Iowa shows a sharp warm-up over the next seven days:

• Tonight (Thu night): Low near 50°F
• Friday, May 22: High near 68°F
• Memorial Day, May 25: High near 85°F
• Tuesday, May 26: High near 85°F
• Wednesday, May 27: High near 84°F
• Thursday, May 28: High near 85°F

That's a jump of roughly 17 degrees from Friday's high to the Memorial Day stretch. Overnight lows start around 50°F tonight, well below the daytime readings later in the week.

Why it matters

For corn and soybean fields across Iowa, sustained daytime highs in the 80s mean faster GDU accumulation. Corn needs warmth to push through emergence and early vegetative stages, and soybeans benefit from warmer soils for even stand establishment. A run of four consecutive days at or above 84°F is worth watching — it could help crops that went in during a cooler May catch up on heat units.

Keep in mind that temperature is only part of the picture. Soil moisture, recent rainfall, and local conditions all play a role. Check locally for the most up-to-date forecast in your county.

What to watch next

• Extended forecast updates: The NWS will refresh its 7-day outlook daily. Watch for any shifts that could pull those mid-80s readings back down.
• Overnight lows later in the week: If nighttime temps also climb into the 60s, GDU accumulation could be even stronger. Tonight's 50°F low suggests the warm-up is still building.
• Soil moisture and rainfall: High temps without adequate moisture may matter for newly emerged stands. Local conditions are worth keeping an eye on.

Source notes

All temperature data comes from the U.S. National Weather Service API (NWS gridpoint forecast for central Iowa). These are forecast values, not observed readings, and are subject to change with each forecast update.