October 2021 was distinguished by having six days with highs and lows that were both in the 60s - the most such days in one month. On average, two or three of these days occur each year, and they've occurred between May and November (ranging from 5/11 to 11/21). September is the month most likely to have such days, and the date most likely to have one has been 9/17 (in nine years). The year with the most of these "stuck" days is 1903, with 13 of them (five other years have had between seven and eleven). 19 years have had none of these days, the last time being in 2019.
Nearly 80% of these days have had measurable rain, with 18% receiving more than an inch, and 75% a half inch or more. The greatest rainfall on one of these days was 3.84" on Sept. 1, 1927. (The last time three inches or more fell on a day stuck in the 60s was on Oct. 27, 2017.) Despite the high likelihood of rain, only two of the last 15 days with temperatures stuck in the 60s had rain.
- Average high/low is 67°/62°, with average rainfall at 0.50".
- The most prevalent high/low is 68°/60°. Nearly 70% of the days had highs of 67°, 68° or 69°, while nearly 75% of the days had lows of 60°, 61°, or 62.°.
- The warmest low on one of these days is 67°, which happened twice: Oct. 1, 1902, and July 20, 1869. The coolest high temperature is 62°, which has occurred four times.
- One of these days had a one-degree diurnal variation (high/low of 66°/65° on Sept. 17, 1869); 12 others had two-degree variations.