Install Conky,

Debian based system, like Linuxmint, Ubuntu, use apt-get install conky
ArchLinux, use pacman -S conky.

Installing Forecast for conky
ArchLinux Install
# yaourt -S conky-forecast

Debian based system Install
# apt-get install conkyforecast if not isn't part of your installation you can download it here.

Copy conkyForecast.config to your home directory and make it hidden.
# cp /usr/share/conkyforecast/conkyForecast.config ~/.conkyForecast.config

Look in this file for more informaiton
# nano /usr/share/conkyforecast/example/conkyrc

Click here for Configuration Setting from http://conky.sourceforge.net

Edit main configuration file.
# nano /etc/conky/confy.conf
add information below, This will give you something interesting to start with:

use_xft yes
background yes
xftfont Liberation Sans:size=6

font Bitstream Vera Sans:size=7
xftfont Bitstream Vera Sans:size=7
xftalpha 0.1

update_interval 1
total_run_times 0
double_buffer yes
text_buffer_size 2048

own_window yes
own_window_type normal
own_window_transparent yes
own_window_hints undecorated,below,sticky,skip_taskbar,skip_pager

minimum_size 300
maximum_width 310

default_color white
default_shade_color 000000
default_outline_color 000000

draw_shades no
draw_outline no
draw_borders no
draw_graph_borders yes

# colours
color1 white
# light blue
color2 6892C6
# orange
#E77320
color3 FC8820
# green
color4 78BF39
# red
color5 CC0000

alignment middle_right
gap_x 20
gap_y 0

no_buffers yes
cpu_avg_samples 2
net_avg_samples 2

uppercase no # set to yes if you want all text to be in uppercase
override_utf8_locale yes

no_buffers yes
use_spacer right

TEXT
$alignc Hostname: $nodename
$alignc Kernel: $kernel
$alignc Uptime: $uptime
${font DejaVuSans:Condensed:Bold:size=20} ${tztime}${font Bitstream Vera Sans:size=9}
${color #B8FF00}CPU:${color white}
#
# How many Cores does your processor have.
Core1:$alignr ${cpu cpu1}%@${freq_g cpu1}GHz ${cpubar cpu1 7,76}
Core2:$alignr ${cpu cpu2}%@${freq_g cpu2}GHz ${cpubar cpu2 7,76}
Overall Usage:$alignr $cpu% $alignr${cpubar 8,182}
${cpugraph 20,}
Highest CPU $alignr CPU%   MEM%
${top name 1}$alignr${top cpu 1}     ${top mem 1}
${top name 2}$alignr${top cpu 2}     ${top mem 2}

${color #B8FF00}Memory Usage:${color white}
RAM ${alignr}$mem / $memmax ($memperc%)
${membar 8}
SWAP ${alignr}$swap / $swapmax ($swapperc%)
${swapbar 8}
Highest MEM $alignr CPU%   MEM%
${top_mem name 1}$alignr${top_mem cpu 1}     ${top_mem mem 1}
${top_mem name 2}$alignr${top_mem cpu 2}     ${top_mem mem 2}

${color #B8FF00}Hard Drive Usage:${color white}
/: ${alignc} ${fs_bar 8,75 /} ${alignr} ${fs_used /}  /   ${fs_size /} (${fs_used_perc /}%)
/home: ${alignc} ${fs_bar 8,75 /home} ${alignr}${fs_used /home}  /   ${fs_size /home} (${fs_used_perc /home}%)
${color white}HDD Read-> ${alignc}${color green}${diskio_read}/s ${alignr}${color #FF0009}${diskio_write}/s ${color white}<-HDD Write
${color green}${diskiograph_read 20,150} ${alignr}${color #FF0009}${diskiograph_write 20,150}${color white}

${color #B8FF00}Network:${color white} ${alignr}IP: ${addr eth0}
${color green}LAN Download:                  $alignr${color #FF0009}LAN Upload:
${color green}${downspeed eth0} k/s                                  ${alignr}     ${color #FF0009} ${upspeed eth0} k/s
${color green}${downspeedgraph eth0 20,150} ${alignr}${color #FF0009}${upspeedgraph eth0 20,150}
${color green}Total:${totaldown eth0}  ${alignr}${color #FF0009}Total:${totalup eth0}${color white}

# For ArchLinux Only
${color2}${execi 30 /etc/conky/pacman-updates}

# This is a graphical way for Weather Information
${offset -5}${color3}${font StyleBats:style=CleanCut:size=12}q ${voffset -2}${font Bitstream Vera Sans Mono:style=Bold:size=11}Weather${font}  ${hr}${color1}
${execpi 1800 conkyForecast --location=CAXX0301 --template=/usr/share/conkyforecast/example/conkyForecast.template}

For ArchLinux Only
This makes pacman-updates work.
Create this file /etc/cron.hourly/pmupdate.sh and add below:

#!/bin/bash
pacman -Sy
return 0;

chmod +x /etc/cron.hourly/pmupdate.sh