GEOFF BENNETT: Welcome to the "NewsHour."

From one end of the country to the other, extreme weather is the top story tonight.

Ferocious heat in the West and drowning rains in the East are making headlines.

AMNA NAWAZ: Both the heat and the heavy rains persisted today, and millions of Americans were left to cope and clean up.

Stephanie Sy begins our coverage.

WOMAN: Oh my God.

STEPHANIE SY: In the outskirts of New York City, roadways turned into rapids.

WOMAN: Look at the people's doors.

STEPHANIE SY: A weekend of heavy rain flooded neighborhoods in the Lower Hudson River Valley, killing one woman who was swept away in the downpour.

In the aftermath, authorities evacuated residents from their homes by boat, cordoned off destroyed streets, and worked to repair downed power lines.

PHILLIPE EDOUARD, New York Resident: My mom, she called me and she said the water was coming in her apartment, had to be pulled out of the apartment complex through the window and then rafted to safety.

The apartment is completely destroyed.

My mother has nowhere to live.

All her stuff is -- there was two feet of water in there.

STEPHANIE SY: It's the latest extreme weather pattern to ravage the U.S. Across New England, residents are bracing for more torrential rain.

States in the West are still sweating through a historic heat wave.

Today, Phoenix baked in highs above 110 degrees for the 10th day in a row, with forecasts showing no letup for the rest of the week.

A similar heat dome has settled over Europe.

Temperatures there climbed to the triple digits over the weekend, impacting cities from Berlin to Madrid, some of the same regions that were afflicted by deadly heat waves last summer.

Today, a blockbuster study was released showing that Europe's 2022 heat waves killed more than 61,000 people.

Published in the "Nature Medicine" journal, the study suggests Europe has not adequately adapted to the realities of climate change.

Extreme weather has also gripped parts of Asia.

Most of China has endured a more than week-long heat wave.

And, in New Delhi, unprecedented amounts of monsoon rain drenched India's capital city, killing 15 people in three days.

SHELLY OBEROI, Mayor of Delhi (through translator): The record of the last 20 years has been broken.

As far as our preparations are concerned, we were fully prepared.

However, the problem of waterlogging arose because of the record rainfall.

STEPHANIE SY: Landslides, floods, fires affecting the world over, and made worse, scientists say, by climate change.

Here in Phoenix, weather experts say its likely that the city will surpass its 18-day streak of 110-plus degree days if the heat wave continues through July 18.

For more on how the city is handling the heat wave, I'm joined by David Hondula.

He leads the Office of Heat Response and Mitigation in Phoenix, which became one of the first cities in the U.S. to create that position last year.

David, it is good to see you.

Thanks for joining the "NewsHour."

So, we're about a week-and-a-half into this latest heat wave.

I wonder what your office has been doing in the last several days to mitigate the dangerous effects of these extreme temperatures?

DAVID HONDULA, Director, Phoenix Office of Heat Response and Mitigation: Well, Stephanie, thanks for having us back on.

And we share your concern that this is a serious public health -- unfolding here in Phoenix and across the communities all across the Southwest.

Heat is our leading or one of our nation's leading weather-related killers.

So we need all hands on deck to help protect vulnerable community members.

And that's certainly some of the work our team has been involved in.

We have really been focusing on direct engagement with some of the most heat-impacted members of our community, sharing heat relief supplies, getting the word out about where community cooling resources are.

And when we can help facilitate connections to critical social services, we find those to be really important connections to make as well.

STEPHANIE SY: Yes, that's a conversation I want to have, because I was just looking at the latest data, and the unhoused still make up more than half of the heat-related deaths in Phoenix.

The city, as you know, David, is currently embroiled in lawsuits over what to do with homeless encampments.

I wonder, do you think encampments make the unhoused more or less vulnerable to death and illness by heat on days like this?

DAVID HONDULA: Stephanie, it's a great question.

And we are seeing some positive signs in the data, although nobody's pleased with where we are in terms of the rate of heat-associated deaths among our unsheltered neighbors.

But we have seen that rate come down over the past couple of years, and we're hopeful to keep moving in that direction.

As we think about campgrounds, shelters, et cetera, we are looking to partner with all of the players who were involved in the recent decision to create what has been called a structured campground that will house our unsheltered neighbors for the foreseeable future to try to make that property really a model of cooling and shade and other amenities that can help protect people from the heat in the summer.

It is a difficult circumstance to be out on the city streets for five or 10 minutes, let alone many hours or an entire day.

But as we transition into this new facility, I think there's a great opportunity for partnership.

We're hearing interest from private sector partners as well on how they can be really part of a successful solution story as we continue to work as a city to get more people into shelter and ultimately housed.

STEPHANIE SY: David, Maricopa County, which includes Phoenix, found 425 people had heat-associated deaths last summer.

That's a record and a 25 percent increase from the year before.

When I interviewed you a year ago, you wanted to reverse that trend.

Why has that been so difficult?

DAVID HONDULA: Heat really exposes and relates to a lot of other social vulnerability factors that we are battling with many partners to try to bring down that number.

As we dissect that very same report, we see the high risks for people experiencing homelessness, the high risks for substance users in our community.

And those aren't excuses to explain why the pattern is happening, but really guide our efforts in understanding where we need to prioritize.

I think we are seeing positive impacts, but clearly much more work to do as we learn what is really most effective to reverse that trend.

STEPHANIE SY: And Phoenix is, of course, not alone.

There's a new report out of Europe today with some startling numbers from last summer's heat wave there, more than 60,000 deaths attributed to excessive heat.

What's your reaction to that study?

DAVID HONDULA: Well, of course, we know there's a lot of work to do, communities all across the globe, in how we improve our response to this hazard.

Whether in the United States or elsewhere, we know that heat is among or perhaps the leading weather-related killer.

And I think, unfortunately, when we see statistics like these, we're seeing the consequence of a governance gap around heat that has lingered for far too long.

Heat has not had a clear problem owner, like other hazards.

And I think that's left communities, including those in Arizona, but really all around the world, behind where they would like to be in preventing -- in preventing those really, really serious impacts.

With respect to comparing those numbers to Phoenix, we, of course, have not seen numbers like those, and we are very hopeful that we never do.

But I think it speaks to some of the preparedness investments that our region has made in the past to help us avoid those particularly catastrophic impacts, of course, different contexts with the availability of air conditioning here compared to other locations.

But we continue to try to engage with communities all across the world to share best practices.

As acknowledged, there's a lot of work to do, and we are all in it together.

STEPHANIE SY: On track for another record-breaking summer.

David Hondula, the Office of Heat Response and Mitigation in Phoenix, thanks so much for joining us.

DAVID HONDULA: Thanks, Stephanie Sy.

And stay cool, everyone.