That's what I'd been lead to believe.

WHO - Philippines are saying otherwise:

https://news.mb.com.ph/2020/02/08/who-ph-2019-ncov-can-survi...

I've been leaning towards this hypothesis lately. We haven't been seeing large increases in cases in countries in the more southern latitudes thus far. Singapore, Indonesia, Thailand India, Malaysia, and Australia have not been reporting large increases in cases like we are seeing in China, Italy, Iran, and South Korea.

Of course there is another explanation, these countries could be under-reporting or not detecting new cases...

I saw a bioxriv preprint that said the virus has trouble surviving outside the human body above 75deg F

On the flip side - the cold tends to keep people indoors and away from others. The warm weather tends to make people go outside and interact with others.