Find hotels in Diagonal, IA from £37

The best time to visit Diagonal, Iowa, for pleasant weather and outdoor activities is generally from late spring to early autumn, specifically May through September.During these months, you'll experience warmer temperatures, making it ideal for exploring the local countryside, visiting nearby parks, or simply enjoying the relaxed pace of small-town life. The summer months, July and August, are the warmest, with average highs often reaching the high 20s Celsius, great for those who enjoy sunny weather.For those who prefer slightly milder temperatures and fewer crowds, May, June, and September are excellent choices. These months offer comfortable conditions for walking and sightseeing, with average highs in the low to mid-20s Celsius. You might also catch local community events or farmers' markets during this period.If you're interested in the changing colours of autumn, late September and early October can also be a lovely time to visit, although the weather becomes cooler and more variable.