Why Has It Rained Every Weekend in NYC and When Will it Stop?

It's going to rain this Saturday, marking the seventh straight rainy weekend in a row in New York City. 

What's happening? Do the weather gods just hate us? That's a question that meteorologists and climate scientists have asked themselves and debated over the years. A 1998 study published in Nature by two researchers from Arizona State University found that "rain is most likely to occur along the Atlantic coast on the weekend and the weather is most likely to be better on a Monday, Tuesday or Wednesday," a phenomenon the authors pinned on the "cloud-seeding effect created by the massive drift of East Coast pollution," and in particular all the pollution from car traffic during the workweek. 

But not everyone agrees with that conclusion. While another study from 1998 found that the northeast had "an excess of wet weekends," that same researcher then stated in a different study a decade later that "neither the occurrence nor amount of precipitation significantly depends upon the day of the week." A 2001 study on rain patterns in the northeast echoed that one, its researchers writing that "this study is unable to detect any weekly cycle in daily precipitation intensity or frequency."

To get some actual answers on why our weekends have been so wet recently, I spoke with John Homenuk, of New York Metro Weather fame, and asked him what's been going on in the atmosphere. As for the idea that weekends are wetter, and that humans are somehow to blame? "There hasn't necessarily been scientific, actual backing to say that the weekends are truly rainier than the weekdays or that pollution is contributing to it," he told me. 

This interview has been lightly edited and condensed for clarity. 

Hell Gate: I think the question everyone in New York wants to know is, why has it been raining every single weekend? 

John Homenuk: So it's a little bit of bad luck, especially at the start of that stretch. We had two weekends, where one of them was tropical remnants, and the other one was just a frontal system that had a lot of tropical moisture along it. So that was bad luck. 

But since then, for the last three or four weekends that we've seen this rain, we really have been stuck in a pattern that has been very repetitive. It's called high latitude blocking. Basically, what it is, is just a ridge of high pressure in the higher latitudes north of New York, typically in Canada, or Greenland, or the Arctic.

And when [these high-pressure ridges] do form, they can control a lot of the weather in our area, specifically, by directing storms towards New York. They don't allow storms to cut to our west or go out to sea. They force storms to amplify, and a lot of times, especially when they're in Canada, like they have been, it directs the storms pretty much right at the East Coast, toward the northeast. 

I call it an atmospheric traffic jam. Basically, we have all these disturbances coming from the Pacific, and this block to our north is not letting them go north of us, so they're kind of directed right at us.

Just for some context, these blocks situated in this area in the winter are associated with some really snowy historical periods in New York. But this time of year, obviously, it's October, so we're not gonna be looking at snowfall. Instead, we're getting something that I consider that might be actually worse, which is like this dreary, rainy, crappy garbage. 

So the periodicity of it has really been unfortunate for us. It very easily could have been that this block set up slightly differently, and the storms were coming through on Wednesday. But instead, it's happening on Friday and Saturday, which really stinks. 

Is it typical that something like this would cause rain on a six- or seven-day cycle?

It's not unheard of. I wouldn't say it's typical. The weather, when it comes to these blocks and when it comes to these events, every one is different. It all depends on what's going on around it and where the block is situated and all that. 

But if you look back at past examples of similar events, there's definitely some, I use the word periodicity. Like, we had a really snowy period in 2010, the winter of 2010. And it felt like for a month straight, we got a snowstorm like every six days. And that period reminds me of this. 

So like, during that winter, you know, it's kind of like people were excited about all the snow. Here, it's kind of just miserable with this rain. 

It sounds like based on your model or prediction that this weekend might be the last rainy weekend we see for a while. 

I would say that the chances go up for a better weekend after this because the block is gone. That being said, it's still a very active pattern, so it's still possible that we have unsettled weather next weekend. But if we do, I think it would be more true bad luck, as opposed to an atmospheric reason as to why. 

To take a step back a little bit, there's been research from the past couple of decades that claims that in the northeast, weekends tend to be rainier than the rest of the week. And that particulate matter from weekday car driving leads to rain on the weekends. What's your take on whether or not that's valid? It seems like there's no agreement. 

You know, there hasn't necessarily been scientific, actual backing to say that the weekends are truly rainier than the weekdays or that pollution is contributing to it. I haven't found any actual scientific backing to the fact that it rains more on the weekends in the weekdays, except for this crazy stretch we're in right now in New York. 

In particular, in the research I've done about the weekday pollution and all that stuff, it has been pretty much debunked. There's not a whole ton of available journals out there, scientific papers on it. 

So for me, my idea of this has always been more conceptual, in the sense that we might not be paying as much attention during the week. You know, we're in the office, or we're inside. So when there's some rain, it's like, whatever. And then, you know, the majority of rain events only last a couple hours, right? And then you come out of the office, and it's not raining anymore.

I think it's more of a psychological thing. On the weekends, we're all hypersensitive to what's going on because we want to go outside, we want to go to the beach, we want to go to the rooftop. And so the weather is even more of a big deal on Saturday and Sunday. That's always been something I've considered, but in terms of actual scientific reasons, you know, I haven't found much evidence that the weekends are rainier here than the weekdays, especially considering there's five weekdays and two weekend days. I think there's just a hypersensitivity to what's going on, on those two days that we have off. 

What's interesting to me, is that there seems to be a lack of consensus on even the data that we're looking at. I was reading that ASU study, and they said that based on their data analysis, which is based on historical precipitation along the northeast coast, Saturdays got an average of 22 percent more rain than, say, Mondays. And then I read this other study by other scientists, and they were like, "We didn't find that at all." As a layperson, I'm reading all this and I'm like, what is happening? 

This is why scientifically, you have peer reviews, and the scientific community reviews these papers and this data, because every data source can be different. It depends on where you're getting your data from. Are you getting it from NOAA? Are you picking it out from individual weather stations? Are you excluding some weather stations? I'm gonna go ahead and assume they didn't include every weather station on the East Coast.

I feel like there's some ambiguity. So whenever I read a scientific paper or a journal, my first thing that I do is, I look to see where the data came from, and was it reviewed and approved and published. What are the comments on it and who wrote it? 

I'm not trying to undermine any papers, people put a lot of good work in. But we know the weather doesn't function on timescales. And the weather has no idea that we are working Monday to Friday. So I've always severely doubted the fact that it rains more on the weekends than it does on the weekdays.

And something like the pollution argument, to me, is a little bit kind of wonky, because if we were causing rain on weekends by driving cars Monday to Friday, we'd have much bigger problems than slightly rainier weather on the weekends. To me, this issue with the data when it comes to weather reports, is far-ranging, which is I think what you're alluding to, and I encourage everyone who reads a paper, who goes into a journal, to make sure that you check your sources and your data and that it's reviewed and approved. Because there's a lot of stuff out there that's a little bit off-center when it comes down to stuff. 

What is not in dispute, at least I hope, is the fact that especially in the northeast, we can definitely anticipate more extreme weather events, due to the effects of human-driven climate change. 

For sure. I don't think there's any doubting that. And I feel generally, as a society, we've come to agreement on that now, which is a change over the last 10 years. When I started forecasting, there was still a lot of hoopla about it. And now it seems pretty much agreed upon, that that's happening. 

Hopefully that's not foreshadowing for the other stuff we still disagree on because it's like, oh, now we agree on it, but 10 years has passed, you know. So can we be a little more proactive now? That's kind of my thing.

What's your prediction for how the fall and winter will look? Are we gonna be buried in snow?

No, I don't think so. In fact, I'm working on our winter forecast right now, and not to provide any spoilers, but I think we're going to trend a little warmer than normal going into November and especially in December. So there'll be some frustrated snow lovers out there in December for sure. 

But the second half of the winter, I think particularly from January onward, could offer some hope for some snow and volatile weather. So it's going to be active, and I keep joking around to colleagues to get some rest. 

Especially coming off last year—I mean, six inches of snow will seem like a blizzard for New York at this point. So I think it'd be a fun one. 

Last year was great. I didn't have to dig my car out once. 

People were really frustrated though, I gotta be honest. Ninety percent of the comments I got were people being like, where is the freaking snow? And I would reply and be like, doesn't everyone hate this? Now it's gone and you want it back? So I was blown away. That was all the replies in our inbox, just people waiting for snow last year. 

New Yorkers will famously complain about everything.

Yes, myself included.

What sorts of comments have you gotten the past few weeks about the rain? 

It's been a lot of that, just like, 'when is this going to end' kind of thing. And this week in particular, the media and the inquiries about the rain have, like, quadrupled because seven weekends in a row was getting crazy. 

This is my favorite kind of weather event, though, because other than the one weekend that was really bad, it's relatively harmless. But people are fascinated by it. And so I think it's really cool that people are learning about the weather and talking about it. So I've had a lot of fun the last couple of weeks, obviously other than the flooding event, which was just terrible. 

I've been joking around like, what did we do to displease the weather gods? Who do we need to kill? Who do we need to sacrifice? 

I think we need to take it as a lesson to try to enjoy the rainy days if we can. That's what I keep saying. Last spring and part of the summer, we were in a drought. And now it's definitely the opposite of that. 

There's some magic to a rainy day in New York, and I know it sucks to have it on the weekend. But it's a great day to go to your favorite bar or cozy up at a coffee shop. And the city is great on a rainy day too. So I keep encouraging people to get out there and try to take it in for, you know, the mood that the rain brings.