In 2020, LEGO released 16 Seasonal sets across 6 subthemes, all of these sets have been retired. Subthemes for that year included Birthday, Chinese New Year, Chinese Traditional Festivals, Christmas, Easter, and Halloween. For that year, the total price of all retail sets cost $348, today those sets are valued around $605, a growth of 74%.
Most valuable 2020 LEGO Seasonal set
80105 Chinese New Year Temple Fair $140.19
Highest growth 2020 Seasonal set
40382 Birthday Set +180.45%
Most owned 2020 Seasonal set
40410 Charles Dickens Tribute
16 sets

30550 Easter Bunny

Theme / Subtheme Seasonal / Easter
Year 2020
Pieces 67
Availability Retired
30550 LEGO Easter Bunny
Retail $4.99
Value $12.22
Growth  +144.9%
Annual growth 10.1%

40355 Year of the Rat

Theme / Subtheme Seasonal / Chinese New Year
Year 2020
Pieces 162
Availability Retired
40355 LEGO Year of the Rat
promotional
Value $32.94
Annual growth 11.5%

40371 Easter Egg

Theme / Subtheme Seasonal / Easter
Year 2020
Pieces 239
Availability Retired
40371 LEGO Easter Egg
promotional
Value $14.99
Annual growth 35.4%

40382 Birthday Set

Theme / Subtheme Seasonal / Birthday
Year 2020
Pieces / Minifigs 141 / 1
Availability Retired
40382 LEGO Birthday Set
Retail $12.99
Value $36.43
Growth  +180.4%
Annual growth 35.4%

40410 Charles Dickens Tribute

Theme / Subtheme Seasonal / Christmas
Year 2020
Pieces / Minifigs 333 / 3
Availability Retired
40410 LEGO Christmas Charles Dickens Tribute
promotional
Value $41.44
Annual growth 36.3%

40416 Ice Skating Rink

Theme / Subtheme Seasonal / Christmas
Year 2020
Pieces / Minifigs 304 / 2
Availability Retired
40416 LEGO Christmas Ice Skating Rink
Retail $19.99
Value $24.00
Growth  +20.1%
Annual growth 3.3%

40423 Halloween Hayride

Theme / Subtheme Seasonal / Halloween
Year 2020
Pieces / Minifigs 148 / 3
Availability Retired
40423 LEGO Halloween Hayride
Retail $12.99
Value $24.46
Growth  +88.3%
Annual growth 9.7%

40424 Winter Snowball Fight

Theme / Subtheme Seasonal / Christmas
Year 2020
Pieces / Minifigs 149 / 2
Availability Retired
40424 LEGO Christmas Winter Snowball Fight
Retail $12.99
Value $24.99
Growth  +92.4%
Annual growth 12.1%

40426 Christmas Wreath 2-in-1

Theme / Subtheme Seasonal / Christmas
Year 2020
Pieces 510
Availability Retired
40426 LEGO Christmas Wreath 2-in-1
Retail $39.99
Value $49.71
Growth  +24.3%
Annual growth 3.9%

80104 Lion Dance

Theme / Subtheme Seasonal / Chinese Traditional Festivals
Year 2020
Pieces / Minifigs 882 / 8
Availability Retired
80104 LEGO Chinese Traditional Festivals Lion Dance
Retail $79.99
Value $114.00
Growth  +42.5%
Annual growth 4.0%

80105 Chinese New Year Temple Fair

Theme / Subtheme Seasonal / Chinese Traditional Festivals
Year 2020
Pieces / Minifigs 1,664 / 14
Availability Retired
80105 LEGO Chinese Traditional Festivals Chinese New Year Temple Fair
Retail $119.99
Value $140.19
Growth  +16.8%
Annual growth 4.6%

853990 Easter Bunny House

Theme / Subtheme Seasonal / Easter
Year 2020
Pieces / Minifigs 57 / 1
Availability Retired
853990 LEGO Easter Bunny House
Retail $7.99
Value $16.42
Growth  +105.5%
Annual growth 5.8%

854037 Christmas Ornament Santa

Theme / Subtheme Seasonal / Christmas
Year 2020
Pieces 44
Availability Retired
854037 LEGO Christmas Ornament Santa
Retail $7.99
Value $20.37
Growth  +154.9%
Annual growth 10.2%

854038 Christmas Reindeer Ornament

Theme / Subtheme Seasonal / Christmas
Year 2020
Pieces 34
Availability Retired
854038 LEGO Christmas Reindeer Ornament
Retail $7.99
Value $15.00
Growth  +87.7%
Annual growth 9.3%

854049 Pumpkin & Bat Duo

Theme / Subtheme Seasonal / Halloween
Year 2020
Pieces 131
Availability Retired
854049 LEGO Halloween Pumpkin & Bat Duo
Retail $9.99
Value $18.99
Growth  +90.1%
Annual growth 7.0%

854050 Snowman & Reindeer Duo

Theme / Subtheme Seasonal / Christmas
Year 2020
Pieces 126
Availability Retired
854050 LEGO Christmas Snowman & Reindeer Duo
Retail $9.99
Value $18.86
Growth  +88.8%
Annual growth 16.7%