September comes with record-breaking chill

Another record down in this summer-that-never-was.
The capital awoke Friday to the chilliest September 1 ever, with Environment Canada reporting 6 C as of 5 a.m. at the Ottawa airport.
We’re headed to a mainly sunny 17 C then down to an overnight low of 3 C with the risk of frost.
Frost!
Weather historian Rolf Campbell tweeted Thursday that if Ottawa’s Friday forecast of 6 C came true, it would be the capital’s coldest Sept. 1 since 1931.
Average first frost in the capital is O