::: Introduction

Weather has an important role in our life each day because we live on the earth's surface and thus we live "immersed" in the atmosphere. We are privileged spectators who can observe a lot of physics phenomena due to atmospheric dynamics. Weather influences both our actions (for example, wearing warmer clothes when it is cold, carrying an umbrella if it rains, going to sea if it is warm, etc.) and our health, wellness, and humour: everyone knows how it is difficult to breath and how we easily sweat during warm and humid evening in summer. How many of us get nervous when a day is very windy (here in Pisa we usually call these days "Libecciate"), how many feel bone or joint pain when weather conditions change abruptly and quickly. Weather involves life of people so much that a lot of us have a sort of confidence with quantity as temperature, humidity or pressure, especially during recent years because both media and a large number of websites are continuously showing weather forecast for next days. However, if we are not satisfied of a weather qualitative knowledge and we want to do quantitative and scientific measurements of meteorological variables, the situation becomes a bit more complicated.

I have been loving meteorology since I was a child. Driven by my own curiosity to understand Pisa's climate , I have started to do first measurements in October 2003, as if it was a game. I bought a simple weather station and started to write on a notebook the most important temperature data for each day. After 5 years, with time, passion, experience and study, I got a more complete weather station (Oregon Scientifc WMR928NX) which can measure temperature, humidity, rainfall, pressure and wind speed and direction, and I have started to manage data completely through a pc. Shortly after I decided to create a website (Pisa Meteo) where to put all the measured weather data by my weather station and to make them visible for all to see. Afterward, in December 2011, I purchased a new and more powerful semi-professional weather station (Davis Vantage Pro 2), so I could improve the quality of measurements.

This website does not provide meteorological forecasts but only real-time weather monitoring 24 hours on 24 and observed weather conditions during past days for Pisa city. Live data may be seen both in tables and in an animated display which refreshes every 5 seconds, whereas recent past data refer to last 24 hours, last 7 days and last 30 days. Then it is possible to see and download a data archive which contains a large number of observed weather data and climate statistics for each month and for each year from the beginning of monitoring.

Real-time weather data may be used as support tool in case of very adverse meteorological conditions but they also may be used only to satisfy curiosity of people (from Pisa or from every other place in the world), by promoting a more scientific approach to this discipline. Furthermore data archive may be used for meteorological and climate research, for example to study the actual climate change so debated in these years. It also may be used for engineering studies: in fact it often happens it is useful to know how much rain falls during a whole year (for example to study protection interventions from rivers flood waves, to project sewers, etc.), or mean temperatures, mean wind direction (for example to exploit eolic energy), or the number of extreme events and a lot of other informations.

Beside meteorological data it may be observed also images of the sky above Pisa and surrounding landscape. Live images are captured by a webcam placed on the roof and are sent to the website every 5 minutes, so a very detailed information on current weather conditions is provided. Images are stored in a webcam archive which allows to observe again sky conditions every day during the year.