The natural-gas burning parts of North America are likely to experience a colder winter if La Niña emerges. Today, US weather forecaster CPC pegged the odds of La Nina emerging in Sept-November at 66% and persisting throughout the winter.
There is plenty of variability but during La Niña, the Northern United States and Southern Canada often see colder than average temperatures, especially in the Northwest and North-central regions. The Midwest and Northeast United States often experience more variable conditions, but there's often a tendency towards colder, wetter weather and more snowfall.
In terms of markets, that kind of weather could help to tighten natural gas markets and for the broader economy a cold winter could put a damper on spending. The shift in spending could be particularly stark given how mild last winter was.