First we do  elementary exercises.  And then dive in.  
To execute any command hold SHIFT and press RETURN

2+4

Print["My name is Mansa Moosa, and I take learned men and women on the Hajj and give each a bag of gold. "]

We are going to immediately dive in and see the full power of the software with fairly advanced example.  But we will go back to simple examples later.  This is just an example to show you that you are not learning something useless.  

Let’s make charts of some weather data for Timbuktu in Africa

What has happened to the temperature and rainfall over the last decade ? 

If we have Internet access, then the command WeatherData[“location”,”parameter”,{date1,date2} ] provides access
to a lot of worldwide data.    

If we do not have internet access then I have downloaded the data and we will use it from a file.  We will learn how to do that in a minute.

(* <<"Documents/talks/Africa-lectures/units/unit1-intro-to-pi/windhoekdata.mx" *)

First let’s plot the daily temperature in Timbuktu and Windhoek.

timbuktutemp =  WeatherData["GATB","Temperature",{{1990,1,1},{2022,12,31},"Day"}]

windhoektemp= WeatherData["FYWH","Temperature",{{1990,1,1},{2022,12,31},"Day"}]

chicagotemp= WeatherData["KORD","Temperature",{{1990,1,1},{2022,12,31},"Day"}]

milanotemp = WeatherData["LIMC","Temperature",{{1990,1,1},{2022,12,31},"Day"}]

milanoprep = WeatherData["LIMC","TotalPrecipitation",{{1990,1,1},{2022,12,31},"Day"}]

jaipurtemp= WeatherData["VIJP","Temperature",{{1990,1,1},{2022,12,31},"Day"}]

We will now make a plot. Do not worry about all the complicated syntax below.  You will learn in as you practice. 
Notice that the temperature a pattern from winter to summer.  But the overall trend seems to be slightly lower. Some days in recent years appear to be quite cold.  Now this is the average temperature during each day. We should look at the maximum and minimum temperature each day.

DateListPlot[timbuktutemp,Frame-> True,FrameLabel->{"Date","Temp C","Airport Captured in 2012"},LabelStyle->Directive[Bold, Large,Italic],FrameStyle->Bold]

DateListPlot[windhoektemp,Frame-> True,FrameLabel->{"Date","Temp C"},LabelStyle->Directive[Bold, Large,Italic],FrameStyle->Bold]

DateListPlot[chicagotemp,Frame-> True,FrameLabel->{"Date","Temp C"},LabelStyle->Directive[Bold, Large,Italic],FrameStyle->Bold]

DateListPlot[milanotemp,Frame-> True,FrameLabel->{"Date","Temp C"},LabelStyle->Directive[Bold, Large,Italic],FrameStyle->Bold]

fermitemp= WeatherData["KDPA","Temperature",{{2020,4,18},{2022,4,28},"Day"}]

fermitempmin= WeatherData["KDPA","MinTemperature",{{2020,4,18},{2022,4,28},"Day"}]

fermitempmax= WeatherData["KDPA","MaxTemperature",{{2020,4,18},{2022,4,28},"Day"}]

DateListPlot[{fermitemp, fermitempmin,fermitempmax},Frame-> True,FrameLabel->{"Date","Temp C","Min and Max Temperature at Fermilab"},LabelStyle->Directive[Bold, Large,Italic],FrameStyle->Bold]

The Weatherdata function allows access to the minimum and maximum temp each day.

windhoekmintemp= WeatherData["FYWH","MinTemperature",{{1990,1,1},{2022,12,31},"Day"}]

windhoekmaxtemp= WeatherData["KORD","MaxTemperature",{{1990,1,1},{2022,12,31},"Day"}]

We will now plot the minimum and maximum on the same picture.  Do not worry if this is complicated.  The point of this exercise is to give you a quick look at what power you have at your fingertips ! We will learn how to use this 
power in the next two days.  

Notice that some of the nights in the last few years have gotten very cold in Namibia. Have any of your noticed this ?
Some nights are less than freezing.  Also, when you look at the max and min, you see that warm days appear hotter and cold nights colder in recent years.

DateListPlot[{windhoekmintemp,windhoekmaxtemp},Frame-> True,FrameLabel->{"Date","Temp C","Min and Max Temperature in Windhoek over 3 decades"},LabelStyle->Directive[Bold, Large,Italic],FrameStyle->Bold]

Let’s quickly learn how to get help from Mathematica on any command.  The precede the command with a question mark (?).   If you want more then click on the >>.

?WeatherData

Let’s get data on rain.  This data is averaged over a week

windhoekrain= WeatherData["FYWH","TotalPrecipitation",{{1990,1,1},{2022,12,31},"Month"}]

jaipurrain= WeatherData["VIJP","TotalPrecipitation",{{1990,1,1},{2022,12,31},"Month"}]

DateListPlot[{windhoekrain,jaipurrain},Frame-> True,FrameLabel->{"Date","Precipitation cm/month","Weekly rain (cm/month) in Windhoek/Jaipur over 3 decades"},LabelStyle->Directive[Bold, Large,Italic],FrameStyle->Bold, PlotStyle->{Green, Magenta}, Joined->True,PlotRange->Full]

DateListPlot[jaipurrain,Frame-> True,FrameLabel->{"Date","Precipitation","Weekly rain (cm/month) in Jaipur over 3 decades"},LabelStyle->Directive[Bold, Large,Italic],FrameStyle->Bold,PlotStyle->Red, Joined->True,PlotRange->Full]

Precipitation data appears to be missing in recent years.

DumpSave["windhoekdata.mx","Global`"]

<<"Documents/talks/Africa-lectures/units/unit1-intro-to-pi/windhoekdata.mx"