So far the highest temperature of the month was on June 20th at 90F

So any chance of resolving 1st to 19th as no?

>Ties are possible.
If 2 tie do they each resolve at 50% or at 100%?

Both at 100%

are the ties determined using Celsius or Fahrenheit?

Let's go with F as it provides more granularity

If you want to look further out than June, try this market:

/ovals/in-new-york-city-on-what-day-will-t-l9h28imppn

The daily peak temperature on the first trio of days were 82F, 80F, and 86F respectively.