Adjusting for heat and humidity

I still haven't quite gotten the knack for figuring out just how much to adjust my pace when running in overly trying conditions. I know that the rule of thumb is about 9 sec/mi for every 5F over 60F, but at what point does the humidity also get factored in? I finally found a table that gives a suggestion for how to factor in the humidity (though it seems like it errs on the overly conservative side -- it certainly does for the temperature adjustment): https://images.app.goo.gl/G3DfxJg5DZ4RyzBm6

Mile    Goal    Actual

1         7:30     7:42

2         7:30     7:27

3         7:30     7:47

4         7:30     7:54

5         7:30     8:00

6         7:30     8:08

7         7:30     8:09

8         7:30     7:59

9         7:30     8:08

10       7:30     10:26 (walked for .29mi because of HR spike)

11       7:30     8:13

12       7:30     8:09

13       7:30     8:22

14       7:30     8:14

Goal Total 1:45:00 (without any adjustments)

Actual Total 1:54:29 (overall pace 8:11)

Looking at HR data from my Garmin, I was actually doing a generally good job of keeping an even HR for most of the run, which fits in with my general impression of doing an even effort across the run (save for that one HR spike). Going a little slower would likely have had my total drop by a couple of minutes, at least, without need for walking for 4.5 minutes