Phoenix Hotel, San Francisco

The hippest pool in San Francisco is now open for day guests. When you book at pass at this legendary rock-and-roll haunt, you'll get towel service, free WiFi, and discounted parking. Thursday through Saturday evenings, you can score cocktails and food next door at Chambers Eat + Drink. If a nap is on your relaxation agenda, The Phoenix can also book you a day room from noon to 6pm ($75, includes pool access).

Hotel Nikko, San Francisco

At downtown's Hotel Nikko, you can get all the benefits of summer pool lounging even when June Gloom descends. Get a seat at the heated, glass-enclosed rooftop pool and whirlpool hot tub. If you’re feeling ambitious, your day pass also gets you access to the hotel’s 10,000-square-foot health club—as well as its sauna and steam room. Snacks and drinks can be purchased from the gift shop at reception.

The Meritage Resort & Spa, Napa

A pool day with no kiddos to harsh your mellow? It’ll set you back just $35 at The Meritage Resort & Spa, a lovely Wine Country estate with hillside vineyard views. A day pass gets you access to the adults-only pool and hot tub, towels, complimentary parking and WiFi, and poolside food and drink service. For just a little more per person, groups can take advantage of a private, shaded cabana with an HDTV and mini-fridge ($350/up to six people or $700/up to 12 people).

The Lodge at Sonoma Resort & Spa, Sonoma

A day pass at The Lodge at Sonoma gives you the freedom to plunge into two adults-only heated pools, soak in two whirlpools, heat up in a barrel sauna, sweat in the gym, and chill out by the fireplace in the quiet relaxation room all day long. A complimentary beverage of choice is also included, and breakfast and lunch are on order at Benicia’s Kitchen. For less than $100 more, you can add on a 50-minute relaxation massage or signature facial. Eighty-minute treatments can also be combined with the day pass.

Rosewood Sand Hill, Menlo Park

This luxe city escape in summer-warmed Menlo Park has everything you need for a day of rest and relaxation. A day pass to the five-star Rosewood Sand Hill, a 16-acre ranch with views of the Santa Cruz Mountains, gets you a full-service lounge chair at the heated outdoor pool, where food and drinks are delivered on request (plus complimentary sunscreen, parking, and WiFi). If you’ve got a crew, splurge on a full, shaded cabana ($500/up to four people), which comes with unlimited complimentary N/A beverages,and can be upgraded to include six beers and a bottle of wine.

Carneros Resort and Spa, Napa

Join the poolside day party at Carneros Resort and Spa the first Sunday of the month all summer long. The 21+ soiree includes access to the estate’s picturesque hilltop pool where complimentary small bites, sparkling wine, and cocktail tastings are served from noon to 4pm with a live DJ soundtrack (a cash bar is open for additional drinks).

For a more serene escape, book a day pass instead, which comes with access to two pools and a hot tub, or a shaded cabana with a TV ($400/up to six people). For an extra fee, you can reserve a combination day pass that includes either a 60-minute quiet mind massage ($275/person) or ageless facial ($300/person), and give you license to relax in the resort’s eucalyptus steam sauna, infinity hot tub, complimentary fitness classes, and lounges.

The Lodge at Tiburon

Drift across the bay for a day of relaxation, Marin style. The Lodge at Tiburon’s day passes include a first-come first-served lounger at the L-shaped outdoor pool and hot tub, as well as towel service and complimentary WiFi and parking. Food and drinks are available for purchase onsite at the Tiburon Tavern by Luna Blu.