Can you convert Fahrenheit-Celsius?

[nei]

A heat index of 46 C would require a 100F temperature with a 76F dewpoint. I'm note sure if I can remember that happening in the last decade in the northeast US

[ColdCanadian]

Originally Posted by Not Made for the South

Really? Wow, does Lake Ontario make things that humid during the hottest days? That's just insane... I can't recall a heat index that high while I've been here, but, then again, I don't live by a body of water.

Actually, we have what I consider an over-sensitive "humidex" in Canada.

Humidex examples:

85 F + 40% RH does not feel like 85 F in Canada; it feels like 95 F
94 F + 60% RH does not feel like 100-105 F in Canada; it feels like 110 F
75 F with 75% humdity does not feel like 75 F in Canada; it feels like 90 F
Even 85 F with 20% humidity still does not feel like 85 F; it feels like 88 F.

Seriously, who ever invented the humidex must be from somewhere as dry as California, or as cold as Labrador!

[ColdCanadian]

Originally Posted by nei

A heat index of 46 C would require a 100F temperature with a 76F dewpoint.
I'm note sure if I can remember that happening in the last decade in the northeast US

We regularly get higher dewpoints that than.
Last summer was cooler than normal, and we still recorded a dewpoint of 77 F/25 C,
even though our highest ambient temp in 2009 was 89 F/31 C.
Our highest dewpoint probably occured when the ambient temp was 84-85 F/29 C.

It's not unusual if we hit a high of 96 F/36 C to have a dewpoint at 80+ F/27+ C.
I've seen dewpoints of 28 C (82 F) at least once since I started watching TV weather stats.

I wonder if "heat island" is a part of that,
along with so many people who water their lawns regularly.

Toronto has a very-high density of population compared with the USA.
Probably less than 10% of land within the Greater Toronto Area is undeveloped or agricultural,
leaving about 90% of the land used for residential or commercial purposes.

With a lot more land area taken up by roads and buildings,
perhaps more of our summer rain evaporates than soaks into the soil,
giving us higher dewpoints.

[ColdCanadian]

Originally Posted by Not Made for the South

That's just insane... I can't recall a heat index that high while I've been here, but, then again, I don't live by a body of water.

Really?
I thought Mississippi was hotter than that.

When I was vacationing in South Carolina in late August,
I found their typical hotter days with heat indexes of 105-110 F (40-43 C) "nice" or "not bad"
and rare days with heat indexes of 115 F (46 C) "a little gross" (98 F/37 C & 83 F/28.5 C dewpoint)