After unprecedented rainfall in July, August, and September (each month had more than ten inches), it appeared a respite was in store during October, as the first half of the month was the driest since Oct. 2000, with just 0.15" of rain measured. However, these dry conditions came to an abrupt end in the last week of the month, as 4.71" was measured - the wettest last week of October on record (and eight of the last nine days had measurable rainfall). Much of the week's rain was produced by a nor'easter on the 25th-26th that dumped 3.69" of rain.
The month's other storyline was its mild nighttime temperatures. There was a record streak of lows in the 60s (13 days), which was also the month's total number of days with lows in the 60s, tying Oct. 1879 for the most on record (the average number of lows of 60+ in October is 4). Lows during the first 12 days of the streak were in the narrow 60°-62° range; Day 13's low was 63°. Of the eight longest streaks of lows in the 60s/70s in October, this year's record streak was the coolest.
Overall, the month was 4.1 degrees above average, and became the sixth mildest October on record (it ranked fourth for average low, and tied for 19th for average high). 17 days were five degrees or more above average; seven days had below average mean temperatures. The most above average day was 10/15, which was thirteen degrees warmer than average (high/low of 79°/63°); the most below average day was 10/1 , which was five degrees below average (67°/51°).
Temperatures during October ranged from 47° (on 10/19, 10/24, and 10/29) to 79° (on 10/15). Only three other Octobers have had a smaller temperature range: 1977 (30 degrees); 2004 (31 degrees); and 1894 (31). This mirrored September, which had a 31-degree variation, and was tied for third smallest variation.
In an oddity, there were six days with temperatures stuck in the 60s - the most on record for any month. They occurred in three pairs, and were concentrated in the nine-day period between Oct. 3-11. This narrow temperature range was largely due to persistent overcast skies.
The season's first low chillier than 50° was reported on 10/18, which was the second latest day for this occurrence (latest is 10/20). Additionally, the month's chilliest reading of 47° (reported on three days), was the mildest chilliest reading on record for October (on average, the coldest reading in October is in the upper thirties).
Here are previous recaps of October's weather: