Scaled data: select year, receiving and transmitting ionosonde and "Update"
In the table numbers of scaled ionogramms (max 360).

Month\Day 12345678910111213141516171819202122232425262728293031
January 288 265 251 200 173 288 282 287 264 269 271 284 286 284 288 282 247 235 241 232 278 288 288 287 288 286 288 285 288
February 281 288 287 286 288 288 288 288 288 288 288 285 204 287 274 285 286 283 288 288 288 288 287 288 288 265 286 257
March 284 288 285 259 273 287 288 280 288 283 287 282 281 271 287 286 287 288 285 285 278 272 279 288 287 270 287 285 288 288 285
April 283 288 288 263 286 268 274 280 270 280 254 266 247 217 122 8 6 2 156 274 257 258 95
May
June
July
August
September
October
November
December
Legend: No data Few (<100) Partial (100–199) Good (≥200)