A follow up question for those well traveled: we are going to several countries and wanted to determine the climate and overall weather, as I have only traveled to the EU before in June/July.

We will be in Amsterdam 4/8/14-4/10/14
Barcelona from 4/10 to 4/16
In Rome, Florence and Venice (and maybe another area) 4/16 thru 4/24
Amsterdam 4/25 thru 4/27
And finally in Paris 4/28 thru 4/30

Lastly, when traveling on local flights from one to the other within the EU, how far in advance do I want to be at the airport? Will 45 minutes to an hour be enough time, or do I need more?
Same question when traveling on high-speed rails- 30-45 minutes before??

Thanks again

The weather is anyone's guess--your best gauge would be to Google historical trends.

Amsterdam would be the most likely for rain and possibly chilly at the beginning of your trip. Good chance of sun in Spain and Italy both with some spring rain.

Follow each airline's check-in requirements to the letter. European budget airlines are particularly un-forgiving on late check-ins and all airlines have factored in increased security clearance times.

"Lastly, when traveling on local flights from one to the other within the EU, how far in advance do I want to be at the airport? Will 45 minutes to an hour be enough time, or do I need more?".

It depends on the airport and the company - they do not all have the same gate closure times.
If you are flying Ryanair, non EU nationals must have their travel doocuments and boarding pass checked and stamped at the Check Desk before going through security in which case 45 minutes may not be enough.
You should check your confirmation e-mail and boarding pass.

Any special reason for returning to Amsterddam? Paris deserves more than 2 days. If you can, I would add the 25th to the 27the to Paris. Do you have your airline tickets yet? If not, I recommend an open jaw flight into Amsterdam and home from Paris.

As for the weather, we use weather.com for seasonal averages. Check it a few days before you leave for trends. You can't get a whole lot of information from people who have traveled a particular time of the year - anything is possible with the weather.

This site has a nice little chart that shows average temperatures and rainfall amounts for each month. It's a useful starting point:
http://www.weather2travel.com/climat...ance/paris.php

I wish it also showed average wind speed. That can be seasonal in many locations, and makes a huge difference in how your day is going. (There are other sites for wind, but I haven't yet found one that lists it nicely with temperature and rainfall like this.)

But as noted, these are all averages, your mileage may vary. Past performance is no guarantee of future returns.

Regarding the airport timing. It depends on whether you will have checked in online and have boarding passes, either printed, or on your phone if the airport / airline accept that, and on checked bags vs carry on.
You will have to go through security, but not passport control.
Your airline will advise on check in time. The gates generally close well before departure time to avoid fines for late departure. I personally think an hour is the minimum time, even with carry-on and a boarding pass.
At some airports it can take a long time just to walk to the gate.

Weather wise, in Amsterdam expect cool and damp, but be prepared for warm and sunny. There is no way of knowing.

There's no need to be at the train station that far in advance. You just need long enough to find your platform and board your train. I usually try to make it there 20 minutes ahead.

THANKS FOR ALL OF THE INSIGHT SO FAR. REASON FOR RETURNING TO AMS ON THE 25TH IS TO CELEBRATE THE FAMED KING'S DAY FESTIVAL ON THE 26TH. DOES ANYONE HAPPEN TO KNOW WHERE THE FESTIVAL IS LOCATED? I HEAR IT'S THROUGHOUT THE CANALS BUT NO REAL INFORMATION FOLLOWS.

I use www.weatherbase.com for historical information about weather.

Thanks for that Kathie. That <i>does</i> have average wind speed. I like it, and was hoping someone here would steer me to a site like that. It is bookmarked and appreciated.

Kings Day is a national day. Every town has a celebration. It is throughout the centre of Amsterdam. It can get very crowded, so be aware of that. Public transport in the city will be very limited, so you will have to walk.