• Hot and dry conditions ahead with temperatures in low-mid 90s and heat index values in mid-upper 90s

• 8-14 day outlook shows continued warmth into late September with slight chance for above normal precipitation

• ENSO update: 71% chance of La Niña transition October-December, signaling potential warm and dry fall/winter

• Chilly temperatures that felt great after a hot summer

• Mostly dry conditions with under 0.4 inches for most of the state

• First freeze of season recorded at Stanley, Iowa (32°F on September 7th)

• Pumpkins: Strong auction prices ($5-10 vs typical $2-3) but poor growing season with fruit set issues

• Cucumbers: Cold damage causing unmarketable scarring at Featherstone Farm

• Melons: Season ended 6+ weeks early, creating H-2A labor contract challenges for growers

• Watermelons: Poor year especially in low-lying areas due to fruit rot

• Flowers: Mixed reports - Rose Farm had great year, others experienced delays

• Honey production: Drastically reduced to 1/5 of expected yields, indicating widespread pollinator issues

• September 11, 1917: Earliest freeze on record hit eastern Iowa with temperatures as low as 30°F, causing considerable damage to corn, potatoes, and other late crops

• Summer Glory Index results and fall foliage outlook

Podcast summary generated using Claude.ai

• Iowa Weather History (1989): Large thunderstorms brought heavy rain to western Iowa with severe weather and brief tornadoes, causing wind damage, roof damage, and trees falling on cars
• 7-Day Forecast: Cool autumn weather with clear skies and below-average temperatures; best rain chances on days 4-6 due to Atlantic activity and shifted Bermuda high
• Climate Outlook: September 9-13 shows slightly warmer temperatures and higher precipitation chances in western Iowa; monthly outlook suggests equal temperature chances and wetter conditions statewide

• Past Week: Most of Iowa received below-normal rainfall (0.5" below average), except western/southwestern Iowa which saw above-average amounts
• Cold Snap: Some locations hit around 40°F, causing potential localized damage to sensitive plants like basil but not widespread frost damage
• Summer 2025 Overview: 10th wettest summer in 153 years with 18.5" total precipitation (5" above average); July was 2nd wettest on record; August was drier at 3.4" (0.75" below average)

• Seasonal Pattern: Heavy dews occur in late August/early September due to shorter daylight hours and cooling surface temperatures
• Science: Earth radiates heat overnight while warm air masses remain overhead, reaching dew point and creating heavy condensation
• Crop Impact: Wet leaves from heavy dews can promote foliar pathogens and crop decline

• Foxtail Grass Seeds: Grower concerned about viability of mowed green foxtail; recommended germination testing with moist paper towel method
• Compost Management: While beneficial, compost can raise soil pH and create phosphorus excess due to 1:1:1 N-P-K ratio; rule of thumb: 1% organic matter = 20 lbs nitrogen per season
• Nitrogen in Rainfall: Addressed grower question about delayed flower blooming; rainfall contains minimal nitrogen (0.5-3 mg/L) compared to irrigation water nitrate levels (10+ mg/L); plant greening after rain is primarily due to improved nutrient availability from soil moisture, not atmospheric nitrogen
• Cover Crops: Good timing now for oats and peas establishment; winter rye timing approaching; recommend seeding when rainfall is expected

Episode Summary created by Claude.ai

Weather Forecast & Conditions:

• Cold front moving south from Minnesota will stall over Iowa, bringing rain chances Friday-Sunday
• Expected rainfall: up to 1-1.5 inches in northwest Iowa, less than 0.5 inches elsewhere
• Cool temperatures continuing into early September (50-60% chance of below normal temps)
• First overnight lows in the 40s recorded this past week

Historical Weather Note:

• August 28, 1979: Violent F3-F4 tornado tracked 45 miles across southwestern Iowa, killing 2 people and causing millions in damage

Growing Season Challenges:

• One grower called this "the worst growing season in recent memory" due to excessive rain and heat
• Watermelon season ending 1.5 months early due to persistent rainfall (14 inches over 2-3 weeks)
• Widespread crop diseases including Phytophthora on pumpkins, pepper anthracnose, bacterial spot, and southern rust on sweet corn

Specialty Crop Impacts:

• Cut flower growers dealing with high soil pH (7.7) and nutrient leaching
• Recommendations to remove diseased peppers to prevent further spread
• Discussion of sprayer technology resources for disease management

Looking Ahead:

• Hope for warm, dry fall to help struggling crops mature
• Next week will feature meteorological summer season review and in 2 weeks, the Summer Glory Index results

Podcast summary generated using Claude.ai

• Historic perspective: August 21, 2004 saw unusually cool temps (upper 30s) in northern Iowa - opposite of current conditions
• Hot summer analysis: July averaged 2°F above normal with exceptional humidity (85% of days had above-average dew points)
• Heat index impact: Triple-digit heat index values driven more by high dew points (upper 70s-low 80s) than air temperatures
• Moisture source: Gulf moisture "gate wide open" with southerly winds bringing exceptional humidity to upper Midwest

• Weekend cooldown: Dramatic temperature drop to highs in 70s, overnight lows in upper 40s-mid 50s
• Extended outlook: Southeastern Iowa likely colder late August, September outlook shows warm/dry trend
• Precipitation: Minimal rainfall expected (0.1-0.25") with best chance Friday night into Saturday
• La Niña watch: Potential fall development could affect late October/November weather patterns

• Disease issues: Rhizoctonia root rot affecting snapdragons; tomato brown rugose fruit virus causing uneven ripening
• Pest spotlight: European corn borer infesting dahlia stems and peppers - biological control with Trichogramma wasps recommended
• Growing challenges: Excessive moisture limiting planting windows; late-planted fall crops struggling to establish
• Crop performance: Good pepper year for some growers, but eggplant and tomato fruit set suffering from heat stress

• Penn State cut flower production newsletter
• Utah State University cut flower resources

Coming in September to your favorite podcast platform: Pivot Points, a new podcast exploring the stories of farmers who have made big changes to their farms and in their lives.

Follow the Pivot Points podcast to make sure you get the podcasts as soon as they are released.

Iowa's top 10 historical rainfalls

• 10th Place: Sheridan (Lucas County) - 11.23 inches on August 27th, 1903

• 9th Place: Ionia (Chickasaw County) - 11.25 inches on August 9th, 2021

• 8th Place: Dumont (Butler County) - 11.28 inches on July 17th, 1968

• 7th Place: Castana Experimental Research Farm (Monona County) - 12.02 inches on July 17th, 1996

• 6th Place: Bonaparte (Van Buren County) - 12.1 inches on June 10th, 1905

• 5th Place: Hudson (Black Hawk County) - 12.28 inches on June 1st, 2000

• 4th Place: Rathbun Dam (Appanoose County) - 12.34 inches on August 24th, 2007

• 3rd Place: Le Mars (Plymouth County) - 12.41 inches on January 5th, 2009

• 2nd Place: Audubon - 12.53 inches on July 2nd, 1958

• 1st Place: Atlantic 1 NE (Cass County) - 13.18 inches on June 14th, 1998

• Definition & Media Coverage
  • "Corn sweat" is simply a catchy term for evapotranspiration
  • Justin Glisan was interviewed by major news outlets (Washington Post, CNN, USA Today, CBS)
  • The phenomenon was trending during the hottest week of July 2025 during a heat dome
• Scientific Reality
  • Corn releases water vapor and oxygen through transpiration (not actually "sweating")
  • Adds 3-5% to relative humidity locally (3-5 degrees to dew point)
  • Peak evapotranspiration occurs during corn pollination/tasseling season
  • Iowa has 13 million acres of corn contributing to this effect
• Comparative Analysis
  • Prairie grasses actually have slightly higher evapotranspiration rates than corn
  • Corn and soybeans have very similar ET rates during peak growth
  • Historical prairie landscape would have different hydrology and soil structure
  • Modeling is used to understand these complex comparisons since full-scale experiments aren't feasible
• Weather Forecasting History
  • First tornado warning issued in 1940s by Miller and Fawbush at Air Force base
  • WWII and 1946 weather radar development improved forecasting capabilities
  • 1925 Tri-State tornado killed ~700 people despite warning signs, but no communication system existed
  • Modern forecasting balances accuracy with avoiding "boy who cried wolf" scenario
• Social Media & Public Education
  • Madelynn Wuestenberg urges people to stop sharing corn sweat TikToks
  • Working on program to fact-check weather-related social media content
  • Emphasizes need for agricultural meteorologists with both meteorology and agronomy backgrounds

Summary generated by Claude.ai