Does racing get canceled due to inclement weather?

I recall a day in the past few years that racing was cancelled due to extreme heat.

For the most part, no. However, as has been mentioned, racing may be curtailed in the event of extreme heat. Also, rainy and muddy conditions may induce horse owners to withdraw frpm individual races. Monday's second race originally had 14 entries but 8 of them were scratched, over half of the field.

Racing continues through rain, but racing delays or cancels with thunder and lightning