Athens, Hydra & Delphi in early March

I would be more inclined to visit Nafplio rather than Hydra. Nafplio is on the mainland but it feels like an island as it is on the sea shore. Athenians use Nafplio as a weekend get away.

We have never visited Delphi in the winter however there are ski resorts nearby which suggests that the is a possibility of snow. I got this off of another site.

The weather in march in Delphi is wet (with 79mm of rainfall over 12 days). It should be noted an improvement from the previous month since in february it receives an average of 101mm of rainfall over 13 days.

The climate is relatively cold in that area the month of march, but it is bearable when dressing warm. The thermometer averaged maximum of 13°C. The seasonal minimum is 8°C. Thus, the mean temperature average in march in Delphi is 10°C. Note that seasonal normals are in contrast with those observed in Delphi in the month of march with a maximum record of 23°C in 2009 and a minimum record of -4°C in 2011.

In march in Delphi, the days on average last 11:54. The sun rises at 06:42 and sets at 18:36.

With a bad weather, the month of March is not recommended.
By the way if its ancient sites you are looking for Nafplio has several very good sites within an hour drive including Ancient Corinth, Ancient Nemia and, Epidaurus

Here is why I suggest you consider just Athens and Nafplio.

Athens http://www.flickr.com/photos/stanbr54/sets/72157632121475515/

Nafplio and Peloponnese http://www.flickr.com/photos/stanbr54/sets/72157632094108982/

We just got back from the Rick Steves Greece tour. We stayed at the Acropolis Select hotel, which I would recommend. Great location near The Plaka and it has a roof top restaurant with a fantastic view of the Acropolis. It was my first WOW moment after arriving in Greece. I think the hotel would fit your budget as well.
We loved both Hydra and Nafplio so it would be hard for me to choose. We were there in October and ferry crossing was smooth and easy.

I really like Delphi as a site and have been several times. It’s true that it’s likely to be cold in March. The first time I went was a December day trip and we had sleet. It wasn’t great but the site was still very impressive. If you are really keen on that particular site then go for it, but take warm clothes.

The small town you mention is probably Arachova. I’ve not stayed there for about five years but it was much more traditional and Greek feeling than the town of Delphi itself, which has very much grown up to serve the site. We passed through Arachova on a bus about a month ago and it had grown a bit but still looked pretty traditional. The downside is that it’s around a twenty minute drive to the site which isn’t ideal unless you have a car. We did it by bus and taxi but that eats into your time.

I’m with those who favour Nafplio. From there you can get to Mycenae, Epidavrus and Tiryns with a car and it’s a beautiful town in its own right. We were there in March this year and the weather was much warmer and sunnier than further north.

Alan

Here's another vote for Nafplio vs. Hydra (the latter will be very quiet in March, not much doing or open)... while Nafpllio is vibrant year-round because savvy Athenians like to go there. Stanbr has already provided his fotos to give you a glimpse of its beauty. Those canopied seafront cafes are FAB for enjoying the best sunsets in Greece, and strolling the town is a delight. Even tho it's on the mainland (and SO easily accessible in 2.5 hours on multi-lane highway via rental car or Modern intercity KTEL Bus), it's at the tip of a peninsula, surrounded by the sea, so you can get the "feel" of an island. Nafplio is widely considered THE most beautiful Old Town in Greece, and was called "the proposal capital of Greece" because so many Greeks take their girlfriends there to "pop the question". (In fact an American friend of mine said "yes" to her Greek guy there).

MORE INFO: This great NONcommercial Website http://www.visitnafplio.com -- tells absolutely everything you'd need to know, including transport, where to stay where to dine etc. Despite your AirBnB fanship, I HIGHLY recommend its recommendation for the BEST moderate hotel in Nafplio -- Agamemmnon & specfic front room balcony sea-view. It's affordable (we paid €70 double in JUNE) and the only hotel with direct unimpeded view right on seafront. Transport: You could take the KTEL bus (hourly on the half-hour) and rent a car locally -- but if going to Delphi also, you might as well rent a car at the airport

POSSIBLE SCENARIOS - You need to be strategic, with only 7 days ... and BTW, for the best advice, with such a short stay try to be specific about arrival/departure flights, not only Date but also time of Day, because it affects your options. ( & I hope you aren't counting departure day in your 7!! You'll be exhausted on arrival, it's a long haul from Texas, even if u take one of the 3-4 nonstops from East Coast ... Maybe not good to embark on a drive then! Depends on stamina & arrival time. Some options:

(1) Arr late on Day 1 (2-7pm): - Free shuttle to/from nearby AVRA Hotel (on a beach)to recover jet lag; DAY 2 early AM shuttle to Airport, rental car 3 hours to Delphi for ruins & museum, o'nite at Hotel w. view down mountain (Hotel Pan is a bargain); Day 3 AM drive back partway to ATH (this map - http://euro-map.com/karty-grecii/peloponnes/podrobnaya-turisticheskaya-karta-peloponnesa.jpg - makes routes super-clear) at ELEFSINA turn WEST to Peloponnese & Nafplio. Enjoy Old Town, sunset, romantic dinner) Day 4 - explore local area, ruins, vineyards? Day 5AM --2.5 hour drive back to Airport, flat-rate taxi (€38) to Central ATH hotel Day 5 aft & Day 6 & 7 - Athens sightseeing

(2) Arr early on Day 1(9-11am): - Taxi to ATH Hotel, sightsee Afternoon, early nite to recover Day 2- Acropolis & Museum, other sites Day 3 Early AM - taxi to Airport, drive to Delphi, stay onite Day 4 AM- Drive to Nafplio; stay Nite of Day 4 & 5; Day 6 = Return to ATH (see Epidaurus on the way?) continue ATH sightseeing PM Day 6 + 7.

I was in Greece for about March 23 to April 7th...my memory now. It was winter for the Greeks, but for me it was wonderful weather, if a little warm for walking around and sitting in the sun. I don't see where you live so not sure what weather you like or feel. I think March is perfect, weather wise, for me. I'm not a Nafplio fan. It was fine, but to me I found it typical of any seaside city found anywhere (of course, with a Greek flavor). However, I live on the coast of New England so 'coastal' doesn't mean that much to me without an exceptional coast, which Greece has, but not in Nafplio. I enjoyed Hydra, which would have been the first week in April. Restaurants were open, but the crowds had not yet arrived. So, assuming there are at least some restaurants open in March, I'd much rather go to Hydra than Nafplio. I'm sure if the ferries are running to Hydra then you will be able to eat. It is an enjoyable place to stroll, get lost, and it has some longer, magnificent walks along the coast. I think Delphi is one of the most beautiful places I've ever seen...the view from (fyi). So basically, you need to read about the different locations and see what fits you. For me, there is a lot to do in Athens and there are places to just sit and look at the beauty, and there is beauty in Athens, but some people can't seem to see it. It's an amazing, ancient, busy, living city. That excites me. IMO, YMMV

If I were doing 7 nights and an overnight flight to arrive, I would do Athens. I would also do two nights in Delphi if you like to sit, have a drink, and look at an amazing view after seeing the ruins. You can easily spend all day at the museum and ruins and the new Delphi is worth exploring in itself (but doesn't take long). Also, I'd put Delphi in the middle of the week, bookended by Athens. 7 nights means you have 6 full days. Again, I'd just add one other location and it would be Delphi. Otherwise, you have too many days running around and too few days enjoying.

Wray she's from Texas (see top), not much on coasts. I do agree that READING is key -- and not just on internet. Get some guide books from library (Rough guide, Blue guide, Cadogan guides are good on background & ambience -- older editions OK, you don't use thse for hotel/dining tips). See what appeals to YOU not just what's highly promoted. PS: don't twist yourself into a pretzel just to see the special guard-changing ... theres a small change every hour or so.

For lodgings in Delphi, I recommend Pithos Rooms. We had a good-sized, very clean and comfortable room there. The breakfast was very good, too. Best of all was the very friendly, super helpful owner. It’s been several years, but when we were there, the price was €60/night.
If you rent a car, I recommend a stop at the monastery of Osios Loukas, on the way to Delphi.

HOtel Pan is right on the Main Street, just down from the Gift Shop that also doubles as Bus Ticket Window -- look for sidewalk sign. If staying over night what you do is drive PAST the Ancient Site keeping uphill for about half a mile on same road (to your left is a parapet w. views down the mountan). THe center of village is just really a wider spot in the road where another road joins from right. YOU can find parking, and walk back downhill about 200 yards to Hotel Pan. Owner at desk offered the Back rooms, on the Main floor, and we thought uh, well, let's look at them. Owner took us down a hallway, opened doors to rooms with french doors & balconies. I stepped out on my balcony... and hawks were circling BELOW me ... and it was a perfect view down the mountain, to a valley filled with Olive groves, and just beyond, a silver sea, lit by the setting sun. Aaah. IT was €35 for single occupancy of double room. This was 1st week of june. Included breakfast. (That was 8 years ago, may be €40 for single-occupancy now).

In May, the Museum stays open until 8 pm, so we walked downhill along parapet (surmounted by flags all along), and enjoyed museum at 7pm, (It has very good explanatory signage), then found dinner outdoors on terrace of simple cafe across from giftshop/ticket place. Do NOT MISS drinking the water at Delphi, they bring pitchers straight from the tap and it is Nectar of the Gods. It comes straight downhill from snow-pack atop Mt. Parnassus, pure as god made it. For the morning, we wanted to enter the ruins site promptly at 8 am, to see it ahead of the bus-trip crowds, so the hotelier made us a continental breakfast, just right. You can be high up in the main ruins site, above the theatre & temple of Appollo, by the time u see the busses roll in from athens. Go to the Museum while those people ar still in the ruins. Don't forget, right downhill from the ruins/museum site, is the "Tholos of Athena"... that round columned ?temple? that's on all the Delphi websites. It's unfenced, open 24/7. And you can fill your water bottles from the Castelli Springs there,... delish.

Images of Delphi with a bonus of Meteora.
Delphi and Meteora https://www.flickr.com/photos/stanbr54/albums/72157698930270992

I just spent 4 nights in Athens at the Pan Hotel, it was €80/night for a double room for a single. It might be a tad more for 2 people since it includes a decent breakfast. The location is perfect for a first-night stay. Take the X95 bus from the airport to the end of the line, Syntagma Square - the heart of the city. When you get off the bus, just walk downhill about 2 short blocks to the hotel. It's modern and they are refurbishing the rooms, most are done, the rest should be finished by spring. I was in one of the "old' rooms and it was fine, a bit small. I requested "quiet" and got a rear room with no view. Most of the rooms face the street and have balconies.

For the changing of the guards on Sunday morning . . . the time is 11.00. The ceremony starts at least 15 minutes earlier and you'll want to be there by about 10.30 to get a good place to stand.

From Syntagma you can take the metro to Piraeus to the ferry, but as others have suggested, a Peloponnese coastal town would probably be better than Hydra.