I checked all the way back to 1879 in the West Lafayette records (Purdue & Purdue Ag Farm) & the only Halloween with even a trace of snow was 1917 & 1955.
There have been accumulating snowfall of a few to several inches in October, but none have occurred on Halloween.
The warmest Halloween on record was in 1900 when the high reached 77! Also, it saw the warmest low temperature for any Halloween on record at 63.
Here is a look at the October 2019 daily readings at WLFI:
Peak measured with gusts late afternoon-evening:
46 mph 4 NW Rochester
43 mph Athens
42 mph 5 E Fowler
40 mph Purdue University Airport
40 mph 5 ENE Michigantown
40 mph 4 SW Rossville
40 mph 5 W West Lafayette
39 mph Waynetown
38 mph Attica 5 E
37 mph Kokomo Municipal Airport
37 mph Grissom ARB
36 mph 2 NW Crawfordsville
36 mph Frankfort Municipal Airport
36 mph 1 W Rochester
35 mph Logansport-Cass County Airport
35 mph Delphi
34 mph Covington
34 mph 2 E Kokomo
32 mph Peru Municipal Airport
32 mph 4 SE Linden
32 mph Amboy
31 mph 7 SE Crawfordsville
31 mph Darlington
30 mph Rensselaer-Jasper County Airport
Quite a Halloween from far eastern Ontario to Georgia!
As of 11 p.m., it is 74 with a dew point of 65 at Rutland, Vermont.....
75 with dew point of 64 at Greenwich, New York.....
72 with a dew point of 61 at Whitefield-Mount Washington Airport in New Hampshire....
65 with a dew point of 62 in northern Maine, at Caribou.
Sherbrooke, Quebec, Canada has 68 with a dew point of 64.
Sussex Four Corner, Nova Scotia, Canada has 64 with a dew point of 62.
Grand Etang, Nova Scotia (Northern), Canada has 64 with a dew point of 62.
Watch for black ice tonight on bridges & overpasses, though snow as ended.
Winds will continue to decrease, but lows of 22-26 with clearing skies will still bring wind chills 9-17 by morning.
Much of the day looks mostly sunny & breezy with highs 40-45. However, clouds will increase Friday evening & into Friday night.
After the wind diminishes a bit, it will crank back up. Late evening to part of the overnight, southwest winds may gust 30-45 mph at times.
Temperatures may drop to 32-36 briefly in the evening, then rise to 35-40.
A few spotty rain/snow showers are possible overnight to early Saturday morning.
Then, with a mostly cloudy Saturday, breezy to windy conditions will dominate with some spotty passing snow to snow/rain with highs 35-41.
After 20s Saturday night, highs Sunday should reach 45-52 with gusty winds & sunshine.
After mild surge Monday-Tuesday with strong south to southwest winds, some scattered showers & isolated storms are possible Tuesday.
This unseasonable cold will penetrate deep into the Gulf of Mexico.
We will warm early next week, but note how the pieces of the lingering cold, stable, dry air just linger in the Southeast & get recycled northward with the flow from the south & southwest.
It will take so much time to erode this away.
So, this should keep rainfall coverage to 45% & any storms isolated.
Any severe risk should stay over southeast Texas to parts of the Gulf Coast, as CAPE recovery will be slow given expanse & magnitude of the Arctic air.
It may warm again Thursday after a chilly Wednesday with a wave of showers & isolated storms, but piece of Arctic air will be pulled in, bringing some snow showers possible late Thursday evening as temperatures fall quickly.
We then see a warm surge mix out the Arctic air with a round of rainfall & a few storms possible around November 13-15.
A pretty robust severe weather scenario may evolve with this powerhouse system in the South from Texas to Arkansas, Tennessee to Virginia & southward.
This will occur as a better influx of moisture & CAPE develop with good wind fields aloft & shear overspreading that area.
We will monitor for us, but it looks like it should stay south of us right now.
The flood gate is opened to the Arctic air after that point.
We get much colder & the fire conditions again get very critical in California.
Much of the area west of the Continental Divide will see well-above normal temperatures. Santa Ana winds will enhance the heat & extremely low humidity in California (central & southern).
Here, we are looking at highs in the 20s & lows single digits & teens.
Some very minor snowfalls are also possible with several Alberta clipper-type systems that pass beyond the mid-point of November.
Milder weather with rainfall should occur in very late November to early December at the cold abates for a while.
It should return in a big way after the mid-point of December.