March 30, 2018
Weather report
Update 23 Sept. 2019 There’s a better version of this script available, see here.
Using OpenWeatherMap’s API it is possible to get JSON-encoded forecasts for my local area. I use jq and gnuplot to format the forecast into something that looks good in my terminal:
Date Time °C hPa Kn ° mm/3h
Friday 15:00 7 1025 17 177 0.99
Friday 18:00 9 1022 20 182 1.83
Friday 21:00 11 1019 23 185 1.98
Saturday 00:00 13 1016 24 192 2.02
Saturday 03:00 13 1013 26 197 2.90
Saturday 06:00 14 1011 23 199 2.23
Saturday 09:00 14 1010 19 212 2.21
Saturday 12:00 13 1009 21 208 0.64
Saturday 15:00 13 1007 21 213 0.56
Saturday 18:00 12 1006 19 208 0.14
Saturday 21:00 11 1004 18 210 0.33
Sunday 00:00 10 1003 19 212 0.32
Sunday 03:00 10 1003 21 214 0.17
Sunday 06:00 11 1003 19 217 0.07
Sunday 09:00 11 1005 17 214 0.00
Sunday 12:00 12 1007 15 214
Sunday 15:00 12 1007 12 214
Sunday 18:00 10 1009 8 197
Sunday 21:00 7 1010 6 168
Monday 00:00 7 1011 4 145
Monday 03:00 6 1011 3 136
Monday 06:00 6 1011 2 74
Monday 09:00 6 1012 3 46
Monday 12:00 11 1011 4 68
Monday 15:00 11 1009 6 71 0.05
Monday 18:00 9 1006 7 88 0.08
Monday 21:00 11 1003 11 132 0.22
Tuesday 00:00 11 1001 14 146 0.36
Tuesday 03:00 11 998 16 156 0.43
Tuesday 06:00 10 996 14 164 0.24
Tuesday 09:00 10 994 19 149 0.22
Tuesday 12:00 11 992 22 143 1.77
Tuesday 15:00 12 990 21 150 2.65
Tuesday 18:00 12 990 18 157 2.78
Tuesday 21:00 11 991 15 159 0.15
Wednesday 00:00 11 992 12 167 3.07
Wednesday 03:00 10 993 11 171 0.56
Wednesday 06:00 11 994 9 162 0.22
Wednesday 09:00 11 996 10 179 0.42
Wednesday 12:00 12 998 10 192 0.02
5 day pressure forecast
1025 +-------------------------------------------------------------------+
| |
1020 | * |
| * |
1015 | * |
| * |
| * ** * |
1010 | * * * * |
| * * * * * |
1005 | ** * * * |
| * * * * |
1000 | * |
| |
995 | * * * |
| * * * |
| * * |
990 | * ** |
| |
985 +-------------------------------------------------------------------+
Here’s the script that pulls it all together:
#!/bin/sh
set -e
# Fill in location and api_key here
location=''
api_key=''
units=metric
[ ! -d "$HOME"/dl ] && mkdir "$HOME"/dl
fcast=$HOME/dl/forecast
get_weather() {
curl -sfL -G 'http://api.openweathermap.org/data/2.5/forecast' \
--data id="${location}" \
--data units="${units}" \
--data appid="${api_key}" \
-o "${fcast}"
jq -r '.list[] | .main.pressure' "${fcast}" |
sed 's/\.[0-9]\+$//' >"$HOME"/dl/pressure
}
[ ! -f "${fcast}" ] && get_weather
time_now=$(date +%s)
case $(uname) in
Darwin | *BSD) mtime=$(stat -f "%m" "${fcast}") ;;
Linux) mtime=$(stat -c "%Y" "${fcast}") ;;
esac
[ $((time_now - mtime)) -gt 3600 ] && get_weather
printf '\n\t%-11s%4s%6s%5s%5s%5s%7s\n' \
"Date" "Time" "°C" "hPa" "Kn" "°" "mm/3h"
jq -r ".list[] | .dt_txt, .main.temp, .main.pressure, \
.wind.speed, .wind.deg, .rain.\"3h\"" "${fcast}" |
paste - - - - - - |
while read -r fdate ftime temp pressure wspeed wdeg rain; do
printf '\t%-11s' "$(date -j -f '%F' +%A "${fdate}")"
printf '%5s' "${ftime%:*}"
printf '%4.0f' "${temp}"
printf '%6.0f' "${pressure}"
if [ "${wspeed}" = 0 ]; then
printf '%d' "0"
else
printf '%4.0f' "$(units "${wspeed} m/s" knots |
awk 'NR < 2 { print $2 }')"
fi
printf '%4.0f' "${wdeg}"
if [ "${rain}" != null ]; then
printf '%6.2f' "${rain}"
fi
printf '\n'
done
gnuplot <<EOF
set terminal dumb
set ytics add ('' 0) scale 0
unset xtics
set title "5 day pressure forecast"
plot "$HOME/dl/pressure" t "" pt "*"
EOF
The script is set up for metric data, so you’ll have to edit it if you’re using the imperial system. And you’ll need an API key (available free), along with a location code.