Baby, it's hot outside and it's only going to get worse before it gets better. So with at least four months of sizzling summer temps ahead, we've scouted out our fave hotel swimming pools that are so over-the-top cool that they are worth checking in for.

No pool visits without an overnight stay is the rule at these hostelries. But taking summer weekend rates into account, a dip in some mighty fancy waters is not as pricey as you might imagine. And what refreshing relief.

Of course, there's nothing today like the long-gone, historic Shamrock Hilton pool — big enough that showgirls water skied across it behind a power boat. But there are a number of slick oases of cool waters that offer a welcome break from the asphalt tedium of summer. Here's a look at a handful of enticing water worlds.

Hotel Granduca

Stepping through the doors of this magnificent hotel in Uptown Park is like stepping into Europe. Even without its stunning pool patio in the palm-shrouded interior courtyard, a weekend escape is worth the dinero. Summer rates begin at $179 a night for a deluxe room.

Oh, but the pool area — the beautiful, serene setting truly transports you into a world so far removed from the Houston hustle that you feel as if you are in Old World Europe. If you really want the luxe treatment, you can pony up an extra $95 on weekends ($155 weekdays) and reserve your own private pool cabana for the entire day — so very European.

A bonus this summer for those with ample pocket change is the "Under the Tuscan Sun" package. Starting at $314 per night, this gem includes a Signature Suite with private balcony, Italian sorbets and chilled fruits, Italian Prosecco lunch for two poolside, a sundown cocktail, continental breakfast in Ristorante Cavour and complimentary valet parking and transportation within a three-mile radius. Hotel Granduca is a member of the prestigious Leading Hotels of the World.

Hotel ZaZa

This hipper than hip hostelry's pool is the place for Speedos and teeny weeny bikinis. A youthful Euro vibe permeates ZaZa's Urban Oasis, as the pool and surrounding cabanas are called. Those hanging by the pool are treated to occasional surprises such as popsicles or light bites and water mist sprays compliments of the ZaSpa staff.

"Summer in Za City" packages began at $199 a night and include two drink tickets, a 5 p.m. Sunday late check-out and a buffet breakfast for two. For $25 more, you can upgrade to a poolside villa. For $50, the upgrade is to a suite. The hotel also offers at ZaSpa "Za'll About You" package — for an additional $89, you receive a mini-manicure, mini-pedicure and 25-minute massage.

What better setting in the city than in the heart of the Museum District. Once you've had enough sun, clean up and stroll across Main Street to the Museum of Fine Arts or down a block to the Contemporary Arts Museum or head to the hotel's popular Monarch restaurant.

The Four Seasons Hotel

If you are looking for a resort experience in the heart of the bustling city, this downtown hotel pool, a $4 million piece de resistance, is the place.

Dramatic cityscape views serve as backdrop to the sophisticated pool and cabana area that was completely renovated two summers ago. Amenities include a water wall, hot tub, fire pit (probably won't be using that this summer) and a poolside bar.

Weekend hotel rates start at $209, but a better deal is the "Stay Longer" package, book one night and get the second night complimentary. That package is priced from $250 for the weekend.

The St. Regis Hotel

This inside-the-Loop hostelry has just completed a multi-million dollar renovation and every guest room is fresher than fresh, giving you get that new-car feel upon entering. The pool area is just as pristine and inviting with loungers covered in rich green canvas with pool umbrellas to match.

We had heard that the pool was small and not much to look at — au contraire. It is beautiful and inviting. A bonus here is the exercise room that overlooks the pool. An overnight stay offers great workout opportunities followed by a refreshing dip in St. Regis waters.

The hotel is offering specials throughout the summer weekends with rooms beginning at $199 for the first night and the second night 50 percent less.

Hotel Sorella

OK hipsters, this is the place in the new CityCentre (near the Beltway) where everyone wants to see and be seen. The rooftop infinity pool and event space overlooking CityCentre's central plaza is dressed with luxe loungers, custom lanterns and draped cabanas. The bonus here is that Hotel Sorella's sleek Monnalisa bar is only steps away. Get your tan by day, dangle your tootsies in the waters by night when dramatic lighting makes the pool area appear even more cosmopolitan.

Extras: Poolside light bites are provided by Alex Brennan-Martin's acclaimed Bistro Alex. Overnight guests can get a day pass to the neighboring 140,000-square-foot Life Time Athletic Club (indoor and outdoor pools here) for only $15.

This summer, Hotel Sorella rates begin at $119 for Friday or Saturday night stays.

San Luis Resort, Spa & Conference Center

If you are looking for a true change of scenery, head to Galveston and this 30-acre property overlooking the Gulf Coast (no tar balls as yet). The vast pool and grotto, lavishly landscaped amid a forest of palms, is kid friendly by day and a playground appealing for grown-ups by night. Youngsters are entertained with Dive-in-Movies, a waterslide and plunge pool. For adults, the H2o Ultra Lounge, swim-up bar, private cabanas — these babies furnished with overstuffed loungers and personal flat-screen TVs — are the ticket.

Summer rates begin at $229 on weekends but if your schedule is flexible, the tariff drops to $189 a night during the week.

La Torretta Lake Resort & Spa

It's easily worth the drive north to Lake Conroe to experience the resort's Aqua Park which includes six swimming and activity pools plus a beachfront and Jacuzzis. And it's plenty family friendly. The 3.5 acre lakefront water park features a raised adult pool with infinity edge. A separate Jacuzzi cascades down to the 6,400-square-foot Mediterranean pool lined with chaises and incorporating an outdoor dining area.

The family section is separate and includes a BreezeBuster pool with dual water slides, a Splash Scape kid's pool with in-water playground, a 300-gallon bucket dump, a Pollywogs pool for the youngest in the crowd and a figure-eight Lay-Z-River rapids course. And there is always the sandy beach overlooking a quiet inlet of Lake Conroe.

Room rates begin at $199.