Here are 2010's earliest sightings of resident and migrant butterflies, as reported to Butterfly Conservation.
Summer's here, as you can tell from the weather! Buddleia bushes are in full flower and providing good shows of butterflies in many areas. The last few species of the year are beginning to emerge now.
Last update: 30 July, 2010
| Vernacular name | Scientific name | Date | Location |
| Chequered Skipper | Carterocephalus palaemon | 20 May | Argyll |
| Small Skipper | Thymelicus sylvestris | 4 June | Dorset |
| Essex Skipper | Thymelicus lineola | 17 June | Norfolk |
| Lulworth Skipper | Thymelicus acteon | 4 June | Dorset |
| Silver-spotted Skipper | Hesperia comma | ||
| Large Skipper | Ochlodes sylvanus | 18 May | Cornwall |
| Dingy Skipper | Erynnis tages | 13 April | Sussex |
| Grizzled Skipper | Pyrgus malvae | 6 April | Sussex |
| Swallowtail | Papilio machaon | 19 May | Norfolk |
| Wood White | Leptidea sinapis | 24 April | Surrey |
| Réal's Wood White | Leptidea reali | 30 April | Co. Armagh |
| Clouded Yellow | Colias croceus | 18 April | Isle of Wight |
| Brimstone | Gonepteryx rhamni | 17 Jan | Hampshire |
| Large White | Pieris brassicae | 14 March | Isle of Wight |
| Small White | Pieris rapae | 15 March | Dorset |
| Green-veined White | Pieris napi | 15 March | Devon |
| Orange-tip | Anthocharis cardamines | 3 April | Yorkshire |
| Green Hairstreak | Callophrys rubi | 6 April | Hampshire |
| Brown Hairstreak | Thecla betulae | ||
| Purple Hairstreak | Neozephyrus quercus | 12 June | Isle of Wight |
| White-letter Hairstreak | Satyrium w-album | 20 June | Derbyshire |
| Black Hairstreak | Satyrium pruni | 9 June | Cambridgeshire |
| Small Copper | Lycaena phlaeas | 25 March | Norfolk |
| Small Blue | Cupido minimus | 18 April | Somerset |
| Silver-studded Blue | Plebeius argus | 1 June | Cornwall |
| Brown Argus | Plebeius agestis | 1 May | Somerset |
| Northern Brown Argus | Plebeius artaxerxes | 20 May | Cumbria |
| Common Blue | Polyommatus icarus | 17 April | Hampshire |
| Chalkhill Blue | Polyommatus coridon | 1 July | Hampshire |
| Adonis Blue | Polyommatus bellargus | 13 May | Wiltshire |
| Holly Blue | Celastrina argiolus | 24 March | Berkshire |
| Large Blue | Glaucopsyche arion | 6 June | Somerset |
| Duke of Burgundy | Hamearis lucina | 9 April | Hampshire |
| White Admiral | Limenitis camilla | 16 June | Oxfordshire & Surrey |
| Purple Emperor | Apatura iris | 26 June | Surrey |
| Red Admiral | Vanessa atalanta | 05 Jan | Isle of Wight |
| Painted Lady | Vanessa cardui | 02 March | Somerset |
| Small Tortoiseshell | Aglais urticae | 01 Jan | Wiltshire |
| Peacock | Inachis io | 02 Jan | Isle of Wight |
| Comma | Polygonia c-album | 04 March | Cornwall |
| Small Pearl-bordered Fritillary | Boloria selene | 12 May | Cornwall & Devon |
| Pearl-bordered Fritillary | Boloria euphrosyne | 8 April | Devon |
| High Brown Fritillary | Argynnis adippe | 3 June | Devon |
| Dark Green Fritillary | Argynnis aglaja | 6 June | Devon |
| Silver-washed Fritillary | Argynnis paphia | 13 June | Sussex |
| Marsh Fritillary | Euphydryas aurinia | 7 May | Dorset & Co. Down |
| Glanville Fritillary | Melitaea cinxia | 28 April | Isle of Wight |
| Heath Fritillary | Melitaea athalia | 20 May | Devon |
| Speckled Wood | Pararge aegeria | 19 Feb | Sussex |
| Wall Brown | Lasiommata megera | 10 April | Lancashire |
| Mountain Ringlet | Erebia epiphron | 3 June | Cumbria |
| Scotch Argus | Erebia aethiops | 25 July | Perth & Kinross |
| Marbled White | Melanargia galathea | 14 June | Oxfordshire |
| Grayling | Hipparchia semele | 17 June | Yorkshire |
| Gatekeeper | Pyronia tithonus | 24 June | Yorkshire |
| Meadow Brown | Maniola jurtina | 30 May | Sussex |
| Ringlet | Aphantopus hyperantus | 12 June | Somerset |
| Small Heath | Coenonympha pamphilus | 27 April | Sussex |
| Large Heath | Coenonympha tullia | 5 June | Co. Fermanagh & Wrexham |
These first sightings are gathered as the butterfly season progresses so as to provide up-to-date information about species emergence. They are not reviewed retrospectively by reference to transect data or distribution records and therefore represent what we believed to be the first report of a species at the time rather than a comprehensive analysis of the actual first dates recorded in a particular year.

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