Et c'est Colin qui le dit :
http://thekingoflimbspart2.com/2013/02/01/radiohead-heading-studio-record-album-september/ 
EDIT EDIT EDIT
--- 4/28/13 -----
- Colin confirms that the earliest possible session dates would be in 2014.
----- 1/21/14 -----
- Colin says the band hasn’t entered the studio yet.
----- 1/27/14 -----
- Colin says he “met with ‘Eddie’, Nigel and Thom briefly today, just general ‘talking about stuff and plan-making.’” and that “Phil has been busy making his new album. “
----- 2/21/14 -----
- Jonny says the band is "waiting to get our strength together - it can be a long process."
----- 3/31/14 -----
- Jonny says the band will make a plan at the end of Summer.
----- 7/12/14 -----
- Jonny says the band will start playing, rehearsing & recording in September.
----- 7/15/14 -----
- Thom tweets "all that we want is this to be over we're shutting the hatches and freezing you out"
----- 9/1/14 -----
- Polyfauna 2.0 is released with stems from new music, new Thom Yorke solo material speculation begins.
----- 9/23/14 -----
- The band reconvene and post old artwork and lyrics from "day 2 in the studio", they also mention recording overdubs.
----- 9/26/14 -----
- Thom releases second solo album Tomorrow's Modern Boxes.
----- 10/5/14 -----
- A translated Italian interview with Phil says the "new Radiohead album may take long, 'even 8 months.'"
----- 10/6/14 -----
- Phil releases second solo album, "Weatherhouse".
----- 11/25/14 -----
- Nigel tweets two images off the band working on beats in the studio.
----- 1/19/15 -----
- Phil says the band had "a very good autumn working on new songs, and they'll reconvene in March" for a "big session."
----- 2/21/15 -----
- Jonny works on Junun in India.
----- 3/2/15 -----
- Thom tweets from a piano.
- Phil begins touring.
----- 5/12/15 -----
- Nigel tweets an image of Jonny "mixing Anna Wintour's album."
----- 5/18/15 -----
- Nigel responds to media claims that LP9 is being mixed.
----- 5/28/15 -----
- Nigel tweets DJ-ing software from the studio.
----- 6/17/15 -----
- Jonny mentions trying to arrange Lift in a Dutch interview.
----- 6/25/15 -----
- Phil says "that's been going in fits and starts, but come September it just becomes quite a full schedule."
----- 7/18/15 -----
- Thom & Nigel begin playing Tomorrow's Modern Boxes live shows.
----- 7/20/15 -----
- Thom performs "The Rip" with Portishead at Latitude.
----- 7/28/15 -----
- Rumors begin to circulate that Radiohead have recorded the next Bond theme.
----- 8/3/15 -----
- Phil says the band hope have plans to reconvene in September and hope to "finish a record".
----- 9/6/15 -----
- Composer Robert Ziegler tweets out photos of Radiohead recording with an orchestra.
----- 10/15/15 -----
- A Russian interview with Jonny is (mis)translated as saying "We have finished recording the new album, but we keep it pereslushivaem and change their views on the recorded material. We hope that soon we will have exactly finish it and start to build plans for a concert tour next year."
- Consequence of Sound picks up the story and Jonny and Thom are forced to respond, denying the announcement.
----- 12/4/15 -----
- Thom debuts new songs "Silent Spring" & "Desert Island Disk" along with The Present Tense in Paris.
----- 12/25/15 -----
- New song “Spectre” is released. New black & white style header images appear on Thom & Radiohead's social media accounts.
----- 1/1/16 -----
- Thom tweets "the end of hollow words" (this has been interpreted a number of different ways, some believing it was a late photo upload of fireworks and a New Years resolution, others think it is artwork and note that "hollow words" has appeared in lyrics sheets and it might indicate completion of an album).
----- 1/5/16 -----
- "Dawn Chorus LLC" is discovered. The company was formed by the five members of Radiohead in October 2015. Prior to this, _xendless_xurbia had been formed in July 2007 (3 months before In Rainbows) and Ticker Tape had been formed in December 2010 (2 months before The King of Limbs).
----- 1/11/16 -----
- AtEasers report seeing a "red moon" posted to Stanley's Instagram, quickly deleted. This coincided with news of David Bowie's passing.
- Nigel tweets out a GIF of studio equipment similar to the "from the cutting room floor" clip posted 4 months before the release of In Rainbows.
----- 1/16/16 -----
- Changes to Dead Air Space are detected, specifically on the tour page.
----- 1/19/16 -----
- Geoff Barrow of Portishead tweets Does anyone know when the new Radiohead album is supposed to come out?" (likely unrelated)
----- 1/21/16 -----
- Radiohead are confirmed to headline the Open Air Festival as well as Primavera and Lisbon.
- Consequence of Sound confirms 2016 touring and adds information about a US leg in July. Lollapalooza & Osheaga had previously been rumored by a reputable Inforoo source.
- These three dates are added to Radiohead.com using this new artwork.
- The band remain silent but Chieftan Mews returns to Twitter.
[2](translates to "Wakes up. The treasure hunt can begin." "Go to bed. Hunting is in your dreams") [2]
- Italo (AtEaseWeb member with ties to the band as a South American tour promoter) reveals that he was informed of a May release for the album, he also shares this information:
apart from what I've shared with you lot in the last few days, now that radiohead is finally touring I can say: they were looking at tour possibilities as far back as august 2013, when they were planning a late 2014 tour which obviously didn't take place. this is something that means they have scrapped the whole thing and made new plans at some point during the recording sessions. this means there is probably a great deal of material they've ditched from recording until then (this includes the third man records sessions) so we're in for something seriously well-thought and not just a throwaway selection of songs. I do have an email from my job's hq back in july 2015 mentioning the month of release (which I'm now inclined to believe it's the physical one and not the download) and this comes straight from their booking agent, with whom the company has a great relationship. this is why I'm so convinced of the release month, even if I heard about this in july. this is a major band securing their tour dates way in advance... don't get surprised they registered their new company in october as they were probably very aware of a deadline they set for themselves just to be able to tour this year.
----- 1/22/16 -----
- Consequence of Sound confirms Radiohead are headlining Lollapalooza, Osheaga, and Outside Lands in North America.
----- 1/25/16 -----
- Dead Air Space goes down for an extended period of time, changes are made over the next few days
- Radiohead's Soundcloud lists "2 tracks" while only Spectre is visible, Songkick link is added to Radiohead's Soundcloud.
----- 2/8/16 -----
- Changes made to schedule page & memory hole on Dead Air Space.
----- 2/10/16 -----
- At a gallery show, Stanley (allegedly) says he is "working on new material for the Radiohead album this afternoon, apparently he has produced a lot of stuff but he is trying to nail the album cover." "The general theme of the album artwork was 'weather related'" & "He is creating it using water and oil and how they interact on canvas (or some other arty words)".
----- 2/16/16 -----
- WASTE Central goes down for maintenance.
----- 2/28/16 -----
- Dawnn Choruss LTD is discovered. This is believed to be the company for LP9 while Dawn Chorus LLC is for the tour.
- WASTE sets up a new shop, telling users "please note: this is a new store. existing users will need to create a new account as your previous login will not work."
- thekingoflimbs.com goes down, redirects to WASTE download code.
----- 3/1/16 -----
- Italo is told when the tour begins, confirming that Radiohead will not just be playing festivals in the Summer.
----- 3/4/16 -----
- McQueen Adams (who had previously toured with Radiohead as their videographer says that the album is finished (11:00min) and will be out in "about two months", reinforcing the May info italo was given.
----- 3/8/16 -----
- TheGigRig shares pictures of Ed's live rig for the "upcoming Radiohead tour."
----- 3/13/16 -----
- Promotional artwork for the rumored May 23rd & 24th shows at Le Zenith in Paris leaks.
- Information about an October show in Mexico leaks with March 14th as the announcement date.
----- 3/14/16 -----
- A Dutch promoter confirms Amsterdam shows to be announced at 4pm GMT, LA dates & Paris are also confirmed. Italo confirms May 20th as the start of the tour.
- Radiohead tour is announced.
- New artwork is posted to social media along with new tour posters.
- Some fans report seeing the figure of a witch in the new artwork, possibly a reference to "Burn The Witch".
----- 3/21/16 -----
- Stanley says he has heard the new album and it is a "work of art" and that it is "not finished yet". He says he is "quite busy" and “there’s quite a lot I still have to do."
- Mark Pritchard releases his single "Beautiful People" featuring Thom Yorke.
- Chad Smith of Red Hot Chili Peppers tweets a picture with Nigel mixing their new album, indicating work on LP9 is in fact complete.
- User "reckoner2016" provides the following info:
First time i post here... but been reading all the post since a long time now...
Sorry my english is not that well...
But here is what i have learned yesterday about LP9...
I have a friend working for different music company. he is not a big fan of Radiohead but when i asked him about that new album coming out he told me : "we know it's coming in the beginning of May". He's also in charge of the coming of the next Mark Pritchard album so he add : "this is why we want to bring out the new single with Thom Yorke this week so that it don't get drowned by the next Radiohead". (Pritchard'Lp will be out in may as well).
So Italo is right... again...
I'm as pissed as you are... waiting for this for so long and just learning it won't be out before at least 6-7 weeks...
----- 3/22/16 -----
- Stanley posts that he has begun work on a feature length film, further indication that the album is complete.
----- 4/3/16 -----
- Thom tweets an article saying "No bigger than a ful stop" (an obvious reference to Ful Stop).
----- 4/4/16 -----
- Streaming services remove collectors editions of Radiohead's discography with indications that XL has purchased the rights to the band's music from EMI/Parlophone.
----- 4/8/16 -----
- Thom is spotted in LA and supposedly says that they are "filming".
- A bandmember contracts Endorfina Studio to film in a Polish national park at night, this is against the rules of the park and the production team are kicked out. (This report is later linked to a project separate from Radiohead)
----- 4/10/16 -----
- A non-disclosure agreement is broken on a podcast revealing information about a Radiohead music video directed by Paul Thomas Anderson (who had previously worked with Jonny on There Will Be Blood, The Master and Junun). News of the shooting broke in Los Angeles on the same day that Thom tweeted a picture of a window and a day after Nigel had retweeted a band engineer.
