Why you’re seeing more lightning in Nova Scotia skies this summer

Nova Scotia saw the most lightning ever recorded in the province in the month of July, and almost all of it came from a single weather event.

The latest climate report from Environment Canada shows 26,194 lightning strikes were recorded in Nova Scotia in July.

A massive, lingering storm sparked 23,008 of those strikes between July 21 and 22 when record rainfall led to the deaths of four people and brought historic flooding to the province.

The average number of July lightning strikes in the province is 7,172.

"Everyone knows how exceptional that [storm] was in terms of rainfall, but definitely exceptional in terms of the lightning as well," said Ian Hubbard, a meteorologist with Environment Canada.

"It set a new record for the month of July and it actually set it just in that two-day period."

Hubbard notes the data only covers cloud-to-ground lightning strikes. Lightning that doesn't reach the surface, or cloud-to-cloud strikes, are not included.

Partial Environment Canada statistics for this month show there have been 10,837 lightning strikes from Aug. 1-14.

Nova Scotia Power is also tracking a significant increase in lightning strikes, according to a spokesperson for the utility.

Between 2018 and 2022, there were an average of 314 outages per year involving lightning. So far in 2023, there have been 959, more than three times the five-year average.

Numbers do not equate to trend

Although this season has been very active for thunderstorms in the province, Hubbard said that doesn't necessarily mean a rising trend over the past few years.

"When we do have an event, or a month like we just had in July, it really stands out to people because it is so exceptional," he said.

For example, in 2018 there were only 441 strikes detected in Nova Scotia for the month of July. The next year, it jumped to more than 9,500.

"We see a lot of fluctuating … just between one year to the next. There was a huge jump there but we're not able to look at these numbers and predict a trend," Hubbard said.

Trend or not, the record number of lightning strikes is yet another facet of the historic July 21 storm that some climatologists are calling a "head-scratcher".

"It is just such an outlier that if you graphed it, you wouldn't believe it," said Dave Phillips, a senior climatologist with the federal weather agency.

"We have all these little dots showing the trend or the distribution of lightning strikes and you have this one way up in the corner there standing there like it doesn't belong, and yet it's real. It occurred. And it was this year."

'This is not the last'

Climate change inevitably means more lightning strikes in our future, Phillips said, because there's a direct correlation between the warmth of the atmosphere and the frequency of lightning strikes.

Whether we'll ever see as many single-day strikes as the July 21 storm remains to be seen. But Phillips said the severity of that storm should be a wake up call because it could happen again.

"You couldn't have manufactured all of the conditions that came together to produce the kind of event we saw, and yet we saw it," he said.

A slew of factors led to the storm being so lingering and destructive, according to Phillips. A tropical air mass, warmer ocean temperatures and high stream levels due to an already rainier-than-average summer.

"The fact that these things have occurred in the past, but maybe not in the same intensity and duration and impact, tells us that this is not the last. No one can tell whether this is a thousand-year event, a hundred-year event, or would it occur next year … it's possible and that all of the ducks can line up and give you a repeat."